Stupid Question For the Day about "Home" and "End"

Short Answer:
The program knows where the screen begins or ends.

HOME and END work differently depending on what program you are. PageUp and PageDown work based on the scroll bar on the right hand side of the program, going the percentage that constitutes a "screen" depending on your monitor and resolution size. If you're typing or on a word processor, or in a field where the cursor can move, HOME goes to the beginning of the line and END goes to the END of the line. Try using Ctrl and HOME or END and you go to the very beginning of the editable field or text.

A true WINDOWS program will allow you to use your shortcut keys like this and won't do something funny when you try it.

 

has nothing to do with your page. all "pages" are files (markup files) and have a beginning and end. every high level language has an API that gives you access to the beginning or ending of any file.

 

not really, cache is for performance. it is much faster for a browser to read a file from your local computer than to re-fetch from over the network again. Cookies are for tracking and keeping you authenticated (session cookie) so you don't have to log in to a webpage after every click. Simply put a cookie is a way to make a state less protocol (http) become state full or remember state.

The history, forward, back buttons are part of DOM, Document Object Model. It's a standard for working with markup languages that all browsers and languages follow.

 

hotballa, are you asking in your OP only about internet or web browser pages, or all documents in any application?

The behavior is different for markup languages. The document remains in memory as you have it on your screen, and the program is responsible for tying the HOME key to the beginning and the END key to the end of the document.

I don't see where you're confused.