Databases

What is a Database?

Databases are exceedingly common and are used for many computer applications, both locally and online. However, as frequently used as they are, many computer users are unfamiliar with databases and even intimidated by them. A database is, simply put, an organized collection of data. The manner in which information is entered into a database makes it easy to retrieve, format and manipulate. All that is required is the knowledge of the proper language. When you know how to query a database in the correct manner, it will yield the specific data in the format you request.

Relational Databases

The most frequently used type of database is called a "relational databases." In a relational database, there are several tables containing various information. Each table contains data that all have attributes related to the subject of the table. All of the tables might be interconnected, as well. For example, a retail business using a relational database would likely have one table containing data regarding employees, another with data regarding customers, another table listing inventory and so on. A database user could run a report to find connections between data in different tables, such as the customer table and the inventory table. For instance, it might list the names of customers who have purchased red and purple widgets in the past 90 days.

Setup

Building a database correctly is imperative in order to be able to retrieve information correctly. The first step that must be taken when creating a database is to evaluate what is required of the database. For instance, a business might want tables containing data on products, suppliers and orders while a school may need a database with tables on teachers, students and assignments. Once the table categories have been determined, the database can be created. Reports and forms can be made later to manipulate and combine data in different tables.

Language

Another commonly used term in databases is the SQL - or "Structured Query Language." Because of the acronym, SQL is often referred to as "Sequel." SQL is the computer language used to request, retrieve and manipulate information from a relational database. Once a user learns basic Structured Query Language, she will realize that the data can be manipulated precisely to suit the requirements. For example, "Select" defines what info should be pulled, "From" allows users to specify from which table to pull the data and "Where" allows the users to enter a condition. For example, "SELECT StudentName FROM Classes WHERE Grade=B" might pull a list of the names of all the students from a table named Classes who currently have a B average. With ample time and practice, databases and database language can be mastered by anyone.

Word processing is a term that means using a computer to create, edit, and print documents. Of all computer applications, word processing is the most common.
Here is an example of a document I typed using a word processor. I managed to contain most the formatting exactly how it was on Microsoft Word:

The Care of Plants

You don’t need to read a book to learn about the beauty, variety and popularity of house plants – just look around you. Everywhere you will find them, the impressive indoor gardens in public buildings… tiny pots in windowsills… scores of colourful varieties offered for sale in green shops.

Indoor plants in the home

The charm of house plants may be universal, but millions of them die needlessly each year. You have to face the fact that your house is not particularly good home for them – most plants would be much happier in the moist, bright air of a well-lit laundry! So you just can’t leave them to looks after themselves: each plant needs care and each variety its own particular requirements.

Basic rules

·         DON’T DROWN THEM – roots need air as well as water – keeping the compost soaked at all times means certain death to most plants.

·         GIVE THEM EXTRA HUMIDITY – the atmosphere in certain rooms may be as dry as desert air. For the plants to strive well it is essential to increase the humidity around them.

·         TREAT TROUBLE PROMPTLY – whether you are an expert or beginner, trouble will strike sometime. A plant may become infested with pests, which if untreated may kill the plant or cause the infestation to spread to other plants.

·         GROUP THEM TOGETHER – nearly all plants look better and grow better when grouped together.

The table below shows the temperature and rainfall of some countries were our house plants were originally found.

Country	Min temp. C	Max temp. C	Rainfall cm
India, Assam	9	32	1065
Borneao, Sandak		36	300
Java, Jakarta	19	36	180

As you can see, a word processor has many different functions like text formatting (Italic, Bold etc.) and you can also create a table.

Zipped Folders

Folders that are compressed using the Compressed (zipped) Folders feature use less drive space and can be transferred to other computers more quickly. You can work with a compressed folder and the files or programs it contains just as you would an uncompressed folder. Once you have created a compressed folder (identified by the zipper on the folder icon), you can compress files, programs, or other folders by dragging them to it. You can open files directly from compressed folders, or you can extract files before opening them. You can run some programs directly from zipped compressed folders, without decompressing them. However, to run programs that are dependent on other files, you must first extract them. Compressed folders can be moved to any drive or folder on your computer. You can also share zipped compressed folders with other users, even if they use a different file compression program. You can protect zipped compressed folders with a password. This protects your data if you save it in a shared network folder, attach it to an e-mail message, or move it between work and home on floppy disks.

What does computer formatting mean?

To format a computer means that all your data will be lost. Your operating system, programs, emails, drivers, pictures, everything! All of the updates on your programs will be gone, infarct the every entire program will be gone. Formatting your computer makes your computer clean and new just like the day you bought it. But be warned! Your computer may have even less than it did when you bought it because the salesperson may have loaded it with extra software to make the sale. When you format a computer you are actually formatting the hard drive. This is the main storage component of your computer. It is usually labelled as C drive on your computer.

Reasons why you might need to format a computer: 

• You have built a computer and you must format the hard drive so you can put an operating system on it.
• You have replaced your main hard drive and the new one needs to be formatted.
• Your computer has a black screen on startup. Sometimes formatting can wipe a problem away.
• You have a software problem that is too detailed to fix.
• You have a major virus that you cannot get rid of.

What is defragmentation?

Defragmentation is the process of locating the noncontiguous fragments of data into which a computer file may be divided as it is stored on a hard disk, and rearranging the fragments and restoring them into fewer fragments or into the whole file. Defragmentation reduces data access time and allows storage to be used more efficiently. Some operating systems automatically defragment storage periodically; others require that the user occasionally use a special utility for this purpose. 

Hardware and Software

Computer Hardware 

Computer hardware or hardware means the fixed parts that make up a computer.

Some examples include:

• Processor

• Memory (RAM & ROM)

• Motherboard

• Graphics card

• Network card

• Modem

• USB flash drive

• Hard-drive

Hardware needs software to tell it what to do. Without software, the hardware can not be used.

Software

Computer software (often called just software) is a type of computer program. It means the applications and operating systems used with computers.

The term software was first used in the late 1960s to show the difference from computer hardware, which are the fixed parts of a machine. Before compact discs (CDs) or Internet downloads, software came on "soft media" like magnetic discs and magnetic tape.

System software (or systems software) is computer software or an operating system designed to operate and control the computer hardware and to provide a platform for running application software.

Example: Operating system

A software system is a system of intercommunicating components based on software forming part of a computer system (a combination of hardware and software). It "consists of a number of separate programs, configuration files, which are used to set up these programs, system documentation, which describes the structure of the system, and user documentation, which explains how to use the system.

Examples:

• Word Processor

• Image manipulation software

• Databases

• Media players

What is a computer?

A computer is a machine that is able to take information (input), do some work on or make changes to the information, to make new information (output). Computers have existed for much of human history. Examples of early computers are the astrolabe and the abacus.

Modern computers are very different from early computers. They are now very powerful machines that are able to do billions of calculations every second. Most people have used a personal computer in their home or at work. Computers are useful for many different jobs where automatic functions are useful. Some examples are controlling traffic lights, vehicle computers, security systems, Washing machines and Digital Televisions.

A person (called a user) can control a computer by telling it to do things. Some ways of controlling a computer are with a keyboard, mouse, buttons, touch screen. Some very new computers can also be controlled with voice commands or hand gestures.

Computers can be designed to do anything with information. Computers are used to control factories, which in the past were controlled by humans. They are also in homes, where they are used for things such as listening to music, reading the news, and writing.

Modern computers are electronic machines. A computer is only useful if it has both hardware and software. Hardware is the physical parts the computer is made of - for example keyboard, mouse, screen, tower. Software is the computer programs (mathematical instructions). Software uses the hardware by taking input and changing it in to useful output.

Computers are able to do billions of calculations each second. They can do mathematical arithmetic very quickly but computers do not really "think". They only follow the instructions in their software programs.

Computer programs are designed or written by computer programmers. Computer programs can be written in the computer's own language called machine code. Machine Code has only a few instructions and is based on logic and Mathematical arithmetic. Using machine code is difficult for most human programmers.

Today, programmers usually write programs using a programming language like C++, Java or BASIC. These programming languages can be translated in to machine code later using a program called a compiler.