How do I launch secure empty trash on a mac?

again, preferences of the finder, advanced tab

a way for full removing is to hold alt (option) and pressing empty trash

so essentially what does that do over just trashing?

with an unsecure delete, the data is kept on the hard drive, and will be overwritten as time passes on, with a secure delete (wich takes longer) the data is deleted (not sure if it just overwrites the file with 0’s) and will not be able to be recoverd (so for the record, if you accidentally sercurely delete something…no way of getting it back