There are 3 formats to choose from when entering content in the content management system:

bbtext (default)
text
xhtml

bbtext is the default because it offers the greatest flexability with the least difficulty - effectively you can enter in plain text with some special formatting tags to enhance the text and/or create links - see the bbtext help topic for more information.

text format is used to enter plain text with no formatting.

xhtml is for advanced users who wish to enter full xhtml code directly.