The following script will delete files in a named directory that are older than 14 days and write to a .txt with the path and the files deleted (found this script on another forum..credit to shay):

dir c:\tmp -recurse | where {!$.PsIsContainer -AND $.lastWriteTime -lt (Get-Date).AddDays(-14) } | select LastWriteTime,@{n="Path";e={convert-path $_.PSPath}} | tee c:\oldFiles.txt | Remove-Item -force -whatif

I have 3 questions:

1. What is -lt and what is -le and what is -gt? When would I use each one
2. The script above only deletes file...how can I delete folders as well?
3. The script above is based off of LastWriteTime .. what about CreatedDate or LastAccessed time?