What are the pros and cons of word processing program? which have been less useful or difficult to use
http://www.google.com/search?q=word+processors&ie=utf-8&oe=utf-8&aq=t&rls=org.mozilla:en-US:official&client=firefox-a
There are many word processing programs. Using them is similar to using a typewriter (old-fashioned as that is!), but with obvious improvements, primarily the presence of spell-checkers and the ability to correct errors without making a mess or starting over.
As to the differences among all the different word processing programs, you'll have to read up on each one. I have used Microsoft Word for years and know nothing about others.