Vi (and its popular variant ViImproved) is a small text editor which does a few things, mostly relating to editing text. If small editors with a single purpose and enough features to satisfy most text editing needs appeal to you, then you might want to consider using this editor.
EmacsEditor is a large text editor which does quite a lot of things, not all of which are related to editing text. If you find yourself interested in an application which does many things, but may require more learning to explore its potential, then you might find this editor to be of interest to you.
Both of these editors support many fundamental virtues of text editors such as extensive syntax highlighting, collapsible functions, spell checking, macros, undo-redo, multiple document editing, and a large support community. They are both free, Open Source, mature software. Try them both and choose the one that best suits you.