A traditional computer is primarily made up of 1 Monitor, 1 Keyboard, 1 Mouse and 1 Base Unit. Just the same as a Bicycle is made up of 1 Chain, 2 Wheels and so on. The base unit (known as: the Tower) is made up of the other computer components, such as: the Hard Drive, the CD/DVD Player, the Memory, the Power Supply, the Sockets and so on.
The Base Unit (Tower)
An Apple Specific Keyboard
An Apple Specific Mouse
A Standard LED Monitor
I say traditional computer because these days the computer has become one unit, in the form of the Laptop computer and iMac Computer. It has the Hard Drive, CD/DVD Player, Monitor Screen, Mouse, Keyboard and Sockets built-in to one unit.
The MacBook Pro Laptop computer has a Hard Drive, Monitor Screen and Sockets built-into its one unit
The iMac Computer is similar to the MacBook Pro Laptop computer in that it has a Hard Drive, CD/DVD Player, Monitor Screen and Sockets built-into its one unit. However, it requires a separate Keyboard and Mouse to operate. Two major advantages of the iMac Computer over the MacBook Pro Laptop computer is its bigger monitor screen and specifications. There are normally more sockets and capacity (i.e. memory size and/or hard drive space) with an iMac. A MacBook Pro Laptop computer on the other hand has the advantage of being truly portable/mobile.
The iMac Computer - It has an Hard Drive, CD/DVD Player, Big Monitor Screen and many Sockets built-into it
The computer is just like a bicycle in the fact that when one major component fails the whole thing fails. A bicycle is useless for example if its chain snaps or tyre punctures. And a computer is useless if its hard drive fails or its operating system (i.e. El Capitan or Sierra) becomes severely damaged, as it may mean you can no longer use the computer until some serious money has been spent on its repairs; especially with regards to Apple Mac repair prices.
In the next three sections I will be explaining the common hardware components and what they do, but before I explain them you first need to know some basic but very important Hardware Terminology (Jargon).
Hardware is the terminology used to describe the physical components of a computer, such as the Hard Drive, Floppy Drive, Sound Card, Graphics Card, Modem, DVD Player and so on.
Software is used to describe the files needed to make the Hardware work correctly. A Printer Installation CD for example contains all the files needed to make the Printer, that came with the Installation CD, work with OS X (Mountain Lion or Mavericks). Software is also used to describe a collection of files that work together to make one piece. Microsoft Office 2011 for example is a collection of files that work together to allow you to do different things, such as Type Letters, E-mail Letters, Create Stationary and so on.
An Application (also known as: a Program) is one piece of software that can perform one or more specific jobs for you. A job is also known as a Task. When a piece of software or one application is performing more than one job (task) at a time it is known as Multi-Tasking. Microsoft Office 2011 for example has one application called WORD (for Word Processing), one application called EXCEL (for Accounting) and one application called Access (for Databases). Together they are called Software (or a Software Package), but each piece of software on its own is called an Application. So WORD is one application that does all your word processing and EXCEL is one application that that does all your accounting.
Each application, as mentioned above, can perform multiple jobs (tasks). Microsoft WORD for example can perform a word processing task, a printing task, a spell checking task and so on. Sometimes an application can perform one task at a time and sometimes it can perform more than one task at a time. Microsoft WORD for example allows you to type a letter whilst it is printing something. Therefore it is multi-tasking because it is performing at least two jobs (tasks) at the same time.
Technical Notes: The technical difference between an application and a program is that an application is generally the GUI (Graphical User Interface) you see in front of you, such as the front-end (menus, buttons, settings and pages) of Microsoft WORD, whereas an actaul program is generally regarded as an executable file that performs one or more tasks behind the scenes.....and/or in front of you.
When you want to print a Microsoft WORD document for example you click on the PRINT button of the application called Microsoft WORD. Behind the scenes that PRINT button is programmed to send your print job (document) to the printer. Before any printing can be done though Microsoft WORD has to communicate with the printer program (driver) whose job it is to communicate with the physical printer - It has to check if the printer is switched on (online), if the ink is low and so on. If all is well your print job (document) is then sent to the spooler program whose job it is to put your print job (document) in the queue of any other documents waiting to be printed; until such time it can be printed (or until you press the CANCEL button).
Don't worry too much about using the wrong terminology - Application instead of Program and vice versa - as they are generally interchangable. App (meaning Application) has only become popular in recent years due to Apple Mac products and Mobile Phones - On Windows, and in the earlier years of computing, the word used was Program. The word application was generally unheard of and classed as a scientific (boffin/geek) word!....How times have changed!
With Apple Mac hardware generally costing at least DOUBLE of their PC (i.e. Microsoft) Hardware equivalents it's worth noting that you are not obliged to use Apple Mac products, such as their keyboard and mouse, just because you may of been told or been lead to believe that only Apple products work with the Apple Mac. This is not true. A "Cheap 'N' Nasty" £5 usb pc keyboard, or even a £25 wireless pc keyboard, will do just the same job on your apple mac as a £100 apple mac 'Magic' keyboard.