You may need to record a voice-over, a student reading or a musical performance. This is the most important part of the process. the better your mic, the better your recording. Close miking works best.
Editing allows a margin of error for mistakes and the ability to remove them. Very helpful for trimming extraneous noise from the beginning and ending of a clip.
Sometimes you just want to segue one file into another or join edited files together.
Allows you to enhance a mediocre recording. Remember the first step of getting this right is the source and the mic. Only more elaborate apps include this ability.
Many apps require specific filetypes for audio. Mp3 will work most places. More high-quality types available are .aif and .wav. Most of the time you will convert one of these filetypes to mp3 for web use.
Why: These tools are simple fast and do most of what you need.