What is a text editor?:
A text editor is a program that allows you to edit 'plain text' files including .txt, .html, .php, .cgi, and many more. Unlike a word processing program, no formatting or other information is saved, only the text (or in our case code) itself is saved.
Do I already have one?:
On a Windows computer the default/included program is called Notepad. On a Mac, you can do text editing in TextEdit if you set it to plain text mode (Format > Make Plain Text)
What other options do I have?:
There are a number of programs for Mac and Windows that allow you to edit plain text files that are made specifically for people who are writing code. These programs have varying features such as displaying text in a color coded format so it is easier to pick out mistakes, quick code buttons, showing a preview, or upload capabilities.