If you running numerous PowerShell scripts and need to have feedback on the command output. Then the command Output Start-Transcript could really benefit you. However, if you looking for accounting or auditing then this is not the best way. You have multiple ways to implement this you could:
All your scripts
Run all you scripts within a given session
If want to specify a particular path then use:
Start-Transcript -Path C:\PreviousFiles.txt -Append
Start-Transcript start recording output.
-Path specifies the files path where the transcribed information will be put.
-Append this specifies that you wish to add the new information to the end of an existing file.