There are sometimes two or three terms for each element. Let's decode a few of the more important terms. Operating system refers to a special type of program that makes the computer functional. It's a go-between other programs and the computer's hardware. Windows 95 and 98 are the names of two common operating systems.
Program is another word for software, which is another word for an application.
You type a letter on the computer using a program called a word processor. It's not all that difficult to remember this one-whatever you can physically touch is part of the computer's hardware. So, it's whatever you feel like punching or shooting when something goes wrong. But, you know if you do it will only make matters worse. RAM RAM is a word totally unrelated to hitting your computer.