Common components of the Burrough’s machine are:
Keypads
Lever
Registers
Printers
They were used for scientific, engineering and other calculations involving long numbers. There were limitation in their calculations especially in the areas where many large tables such as logarithm, trigonometric application, etc. Were involved
Database
Database: is a single organised collection of data for one or more purpose stored with minimum duplication of data items so as to provide a consistent and controlled pool of data. For example a school student database will contain data relating to their academic results, school fees, accomodations, parent information and so on for the purpose of managing the students.
Traditional databases are organised by field, record and files.
A field is a single pieces of information.
A record is one complete set of field.
A file is a collection of record.
A database is usually created using database packages called Database Management System (DBMS) and Relational Database Management System (RDBMS).
Database Management System:DBMS: is a software that controls the storage, retrieval and manipulation of data stored in a database. examples of DBMS are Microsoft Access, Oracle, My SQL, Foxbase plus and so on.
Basic terminologies in database
The following are some of the basic database terminologies
Data: is defined as raw fact or unprocessed facts or unknown fact
Field: is a single piece of attribute about an entity, place or event in a student database table, some examples of attribute or field are: surname, date of birth, address e.t.c
Record: A record is a complete set of attributes (fields) about an entity, place or event
Key: A key is an attribute in an attribute in a database table or file. The primary key is a unique attribute that can be used to identify a record in database table.
File: A file is a single collection of related records.
Forms of Database Organization (Database Model)
A database model is a fundamental specification describing how a database is structured and used. That is, how the data is stored, organized, related and manipulated. It defines the set of many data base models but the three basic database models are
Computer database format
Database packages are used to design a database in computer. Example of a common database package is Microsoft access. Microsoft access is a relational database management system used to create and modify databases.
The database format in the computer is organized as follows
To create a database on the computer with MS-Access
Load Microsoft Access
To load access, do the following
Click on start menu
Point to al programs
Point to Microsoft Access
Click on Microsoft access.
Create Database
From the displayed window, click on blank database
By the right hand side of the windows, click inside the file name textbox and type the desired database name.
Click on create command button.
Assignment
Introduction To World Wide Web(WWW)
World Wide Web: also known as www or w3 commonly known as the web is a system of interlinked hypertext document accessed via the internet with a web browser, one can view web pages that may contain text, images, videos and other multimedia and navigate between them via hypertext
Breif history of world wide web
Using concepts from earlier hypertext system, English engineer and computer scientist, Sir Tim Berner's - lee, now the director of www consortium, wrote a proposal in March 1989 for what would eventually become the WWW. At CERN in Geneva Switzerland Berner - lee and Belgian computer scientist Robert Coillian proposed in 1990 to use "Hypertext to link and access information of various kinds as a web of nodes in which the user can browse at will and publicly introduced the project in December.
The World Wide Web was developed to be a pool of human knowledge and human culture which would allow collaboration in remote sites to share their ideas and all aspects of a common projects.
Basic terminologies of internet to be considered are
- WWW: it refers to all the websites, resources and uses in the internet that are using HTTP (hyper Text Transfer Protocol). It is also a universe of network accessible information, an embodiment of human knowledge. The document are formatted in a mark up language called HTML(Hyper text Mark up language )that supports link to other documents as well as graphic , audio and video files .The world wide web is a global set of documents , image and other resources logically interrelated. By hyperlink and referenced with uniform resources identifiers. [URIs] Url allows providers to symbolically identify services and clients to locate and address web servers that store documents and provide resources and access them using the hypertext transfer protocol [HTTP] The primary carrier protocol of the web.
-Web browser: is a software application that enables computer users to locate and access web pages. Browser transfer the basic [HTML] code that allows a user to see images, text, video, and listen to audio on websites and connects to other web pages though hyperlinks. Examples of web browsers: Mozilla ,Firefox, Netscape, Navigator, Microsoft internet explorer, Apple's safari, google chrome and so on.
-Website: it's a collection of a related webpages containing imagee, videos or other digital assets. A website is hosted on at least one web server or a private local area network through an internet adress also called URL.
Benefits of a website
1. Cheaper and flexible advertising
2. Market expansion
3. Promotes e-commerce
4. Support e-learning
5. Increase in sales and revenue earning
6. Offer convenience
7. Improve credibility
8. Growth opportunity
-Webpage: is a website html document that is displayed by a Web browser.
Homepage: it's refers to the initial or main webpage of a website it's the webpage that automatically load when the website is invoked by the web browser.
-Protocols: In computing, a protocol is a set of rules that governs the communication between computers in a network. A protocol is a convention or standard that controls or enables the connection, communication and data transfer between computers in a network.
There are many protocols used in web technology. They are:
HTTP: means Hyper Text Transfer protocol: It is a networking protocol that governs exchange, transfer and distribute html documents in the WWW.
HTML: Hyper Text Markup Language: It is the predominant markup languages for web pages. It is the basic building block of web pages.
SMPT: Simple Mail Transfer Protocol: It is an internet standard to electronic mail (e-mail) transmission across the internet protocol (I P) network.
Uses of WWW
i. Enable access to information from anywhere in the world.
ii. Enables sharing of ideas, knowledge and skill across the world.
iii. Enables social networking, collaborations and making of friends across the world.
iv. Enables e-learning that is highly beneficial to educational systems.
v. It is the bedrock of e-commerce which is an effective trading system.
vi. Enables tele and video conferencing across the globe.
vii. Empowering radio and television broadcasting.
ix. Encouraging view way of working from home.
Navigating through a website
Creating a good website navigation is the important task a web designer has to accomplish in the web design process website navigation is the pathway people take to navigate through the site. It must be well constructed, easy to use.
purpose of navigation
1. To present readers with the most user-friendly path through the classification so that they find the content they want quickly.
2. Ensures that readers always know where they are bin the site.
3. Allows readers to move quickly and logically throw the website.
4. Guides readers the proper context of the document they are reading.
5. Highlight for the reader part of the classification that the organization wants to promote.
Softwares for web development
1. Microsoft front page: it's full name is Microsoft office front page. It is a W Y S I W Y G (what your see is what you get) HTML editor and website administration tool from Microsoft.
2. Macromedia tools: the common ones are dream weaver, flash, fireworks, free hand.
3. Adobe tools: These are adobe dream weaver, fireworks and flash. Other softwares for web development include: studio, coffee cup, notepad and so on.
Assignment
List (10) ten e-commerce site you know.
| Country | capital |
|---|---|
| India | New delhi |
| Germany | Berlin |
| New zealand | Wellington |
Networking
A computer network allows sharing of resources and information among interconnected devices. Network exist for one major reason: to share information and resources.
Types of network
ARCNET: attached resource computer network is a star (LAN) topology network. ARCNET was the first widely available network system for microcomputer and became popular in the 1980s for office automation task. ARCNET was developed by John Murphy of data point cooperation in 1976.
Token ring: token ring (LAN) technology is a ring topology network. It uses a specific three-byte frame called a “Token” that travels around the ring. Physically, when connected through cable to a “HUB” it is the hub that manages the network in a ring topology manner. An example of a token ring network is IBM Token Ring System.
Ethernet: it is a bus topology “LAN” network system “LAN” use coaxial or twisted pair cables to connect computer system.
Network topology
In computer network topology refers to the layout of connected devices. There are two types of network topology. Physical topology and a logical topology.
The physical topology of a network refers to the layout of the cables and network devices. Logical topology refers to the method of communication of the network devices. Network topologies are of communication of the network devices. Network topologies are categorized into the following basic types.
STAR TOPOLOGY: in star topology network, the network devices are connected to the central point like a star. The central point may be a hub, a switch or a router. All the individual network devices communicate with the central point.
Thus once the hub fails, the network is grounded but if any other network devices fail, the network will still be operating without the failed device. Also, the star topology requires more cable because cables are laid form all the network devices to the hub. Data on a star network pass through the hub, switch or concentrator before continuing to its destination. The hub, switch or concentration manages and controls all functions of the network.
Advantages of star network
Disadvantages
Bus topology
Bus network topology uses a common beackbone (a cable) to connect all devices. The backbone is a shared communication medium that all devices are attached or connected.
A device wanting to communicate with another device in the network sends a broadcast message onto the wire that all other devices see, but only the intended recipient actually accepts and process the message. Bus network work best with a limited number of devices but if the backbone cable fails, the entire network fails. Also if any of the devices are down, the network fails. An example of bus network is the Ethernet.
Advantage of bus topology
Disadvantages of a bus topology
Ring topology
In a ring topology, all network devices are connected together in a ring form. That is, every device has exactly two neighbor for communication purpose. All messages travel through a ring in the same direction (Either clock wise or anti-clock wise).
A failure in any cable or device breaks the loop and can shutdown the entire network. An example of a ring topology is IBM Token Ring network and it's hub is the multi-access unit(MAU).
Network devices
The network devices are the nodes of the network . They are device that aif connection and communication. The common network device are:
1. The Hub: it is a device that connect all other devices in a star network together. Every device in the network connect directly to the hub through a single cable. The Hub receives messages from a device and broadcast it to all other devices. Due to the fact that the hub broadcast messages, one message sent by the hub is not able to identify the device that owns the message. This is the reason why people say that the hub is not intelligent.
2. Modem: it's an an acronym for Modulator and Demodulator. It's is a device that can connect a digital data to an analogue data and vice versa.
3. Switches: A switch is a device that channel incoming data from any of the network device to the specific device that is the destination of the data. Unlike that hub, the switch is intelligent because it does not broadcast but channel the data to the specific destination.
4. Bridge: It is a device that connect two similar network together. A bridge will connect or join 2 ring network together or 2 star network. It could connect many similar networks together.
5. Router: it is a network device that connect 2 or more dissimilar network together, for example, a router can connect a ring network with a star network. A wireless network and cable network a LAN with a WAN and so on.
6. Network interface card: NIC: A network interface card/ controller or network adapter, LAN adapter and by similar terms is a computer hardware components that connects a computer to a network.
Benefits of computer networking
1. It helps to enhance connectivity: network connect and link unlimited numbers of computers. This in turn connect the people using this computer.
2. Networking helps in sharing of hardware resources. Network helps in sharing of different hardware devices. E.g a single printer can be shared by Many staff in an office. This saves a lot of cost.
3. Eases out management of data: network provide the advantage of centralization of data from all the users system to one system where it can be managed in an easy wnd better way
4. Internet: Internet is a network that connects different people in different parts of the world.
5. Data sharing
Assignment
Which of the network topology do you consider the best and why?
