difference between equalizer, amplify and normalize


what’s the difference between amplify, equalizer, normalize and the manual adjustments you can make using the envelope tool please. Simple answers would be greatly appreciated

thank you in advance

Amplify and Normalize are very similar effects. They are similar to a “volume control” in that they make the audio louder (higher amplitude) or quieter (lower amplitude).
The difference between Amplify and Normalize is that the Amplify effects increases the amplitude by the amount you specify, whereas the Normalize effect amplifies the audio to the level that you specify.
The difference is described in detail here: http://wiki.audacityteam.org/index.php?title=Amplify_and_Normalize

Equalization is a completely different effect. It is more like a fancy “tone control”. Whereas most hi-fi systems have only “bass” and “treble” controls, the Equalization effect provides powerful control over the frequency content.

You will find details of all of the built-in effects in the manual here; http://manual.audacityteam.org/o/man/effect_menu.html

The Envelope Tool allows you to easily make volume corrections to a performance note by note. You can force the other tools to do that, but that can be insanely painful.