Trimmer tool

Can someone explain me if there is a usual trimmer tool somewhere at Audacity options? By trimmer tool i mean a tool that allows not only to cut audio files but also to come back to cut pieces by dragging the end or the beginning of the track and thereby having the possibility to get to any piece of the original file any time you want.
I just absolutely can’t find it and I don’t believe such a popular program doesn’t have this option. And if it really does not, what is the solution for having cut pieces back? For example if you edit the file the first time, then listen to it again and here you cut some sounds you shouldn’t have to, or just need some phrases back, what do you do? Find these pieces in the original track?

Audacity is a “destructive” editor. When you “delete” (trim) a section of a track, it really is “deleted” from the track and not just “hidden”. If you have not done any other processes then you can get it back by using the “Undo” function (Edit menu or Command+Z).

You can preview a “cut” by selecting the part that you are thinking of removing and then pressing the “C” key.

If you want to delete a section but think that you may want to change it later, make a copy of the track (select the track and press Command+D to duplicate the selection), then click the mute button on the duplicate track so that it does not play.

Never work on an irreplaceable recording without first making a backup copy in a high quality format such as a WAV file.