I wrote before about misuse of To:, Cc: and Bcc: in email communication. This is another one of those posts.
I often get email from customers that lead me to believe that they don't understand the difference between sorting and filtering a list. Usually I come to this conclusion after reading their email, getting confused myself and having to read the same email 2-3 times before I realize "oh yeah, this is another person saying sort when she means filter". Let's go to the dictionary:
a : to put in a certain place or rank according to kind, class, or nature
b : to arrange according to characteristics
a : to pass (something, such as a gas or liquid) through a filter to remove something unwanted
So when it comes to lists, sorting arranges the list in a particular order. Whereas filtering temporarily reduces the amount of record in the list (perhaps so you can focus on a smaller subset).
How do you know which you have done? If the number of records in the list has decreased, then you have filtered.