Let us now talk about something that just messes with every Windows user’s head when making the switch to Linux: Capitalization. So basically, you have uppercase and lowercase letters. In the Windows operating system, it doesn’t care whether you put in an uppercase or a lowercase letter. If you have a folder named “Home” in Windows, that is going to be the same as “HOME,” “home,” or “homE.” Windows, except when it comes to passwords, does not care about capitalization.
In the Linux world, keep in mind that Linux was created by computer professionals. These computer professionals coded the characters of letters, numbers, punctuations, etc. using ASCII text. In ASCII text, an uppercase “H,” for example, is actually a different character from a lowercase “h.” What this means is that in the Linux world, “Home,” “HOME,” “home,” or “homE” would be considered different folders.
Let us say you have a folder named “USER,” but for some reason your typed in “user” when you tried to access it. Linux will not be able to find that folder because the “user” folder does not exist. Only the “USER” folder, with the uppercase letters, does exist. So remember, capitalization matters in Linux.
One of the places this can cause you big problems, and you have probably already seen this with some websites that you use, is when you are typing your username logins. In Linux, all username and passwords are case sensitive. So when you type in your username or password in Linux, make sure that you don’t have your caps lock key turned on or you are not accidentally holding down shift when you type in your username and password.
This is actually not complicated. It is just that people are used to using Windows that they totally bring the mannerisms of using Windows over to Linux, where capitalization matters greatly.