A .rar file is a special type of compressed file that is more efficient than .zip files and is thus commonly used in sending large amounts of data across the internet. Consider the following allegory-
Imagine you are a company and you make clothing. Let's say you made a shipment of 100 shirts and you want to ship them across the world. Your first option might be to ship each of the shirts one by one in little boxes. This is the equivalent of sending normal files across the internet- each file must be downloaded independently, one by one.
Option two is to take all the shirts, fold them up, and put them in a big box fairly tightly packed. This is the equivalent of how .zip files work; all the files are put together in a single, compressed file. This way, it is possible to send a single file that contains many files within it, while at the same time, saving space thanks to compression, and anyone can un-zip the file using the built in utilities on their computer.
Your last and fanciest option is to vacuum-pack the shirts and put them in a single, even smaller box. The only problem is, the guy on the other end is going to need the right tools to un-pack the shirts without damaging them. This is like a .rar file- it achieves far superior compression than .zip files, and also creates a single file that can hold many files. Smaller package = less postage cost = happier customer and happier seller.
Now, like our shirts allegory, there are some important things to note about the behavior of both .zip and .rar files:
1. .zip and .rar files are made by selecting a number of files and telling the computer to
compress
them into an individual file. This is like how you must pack the shirts into the box, you cannot instantaneously poof a box full of shirts. Note that this operation happens by copying the files, not moving them.
2. In a
retrograde
sense, the opposite is true- the files within the .zip or .rar files
cannot
be used or opened until they are extracted from the .zip file, just as you
cannot
wear a shirt while it is still in the box, you must open up the box and take out the shirts so you can find which one you want to wear. Note that this operation, referred to as
"extraction"
, or colloquially as
"unzipping"
or
"un-raring"
is accessible by right-clicking on the file in question (a .zip or .rar) and selecting that option. Click okay to the resulting dialog window and the files will extract to a folder that has the same name as the .zip folder. You will require a program such as
WinRAR
or
7-Zip
to gain this functionality for .rar files.
3. Programs like WinRAR (for .rar) and Explorer (for .zip) allow you to look/browse inside .zip and .rar files, but this action is NOT the same as extraction! It's like shuffling through the shirts without removing them from the box. Remember: always extract/unzip the files before attempting to use them.
You can think of installers as self-unpacking boxes, but make sure you tell them WHERE to un-pack!