There are many ways to “log” your contacts, paper logging, software logging or on-line logging sites typically a combination of these is the latest method. For contesting you will usually be required to submit a log (in Cabrillo format) to the sponsor of a particular contest, an example is to the ARRL for their “ARRL Field Day” (not a contest?)
There are many software programs that log your contacts, will create a Cabrillo file and may even submit it directly to the proper sponsor.
Ham Radio Deluxe (a Complete Ham Radio suite including rig controls)
N3FJP (far more than just logging software)
There are several QSL databases. Some post awards for “Worked All States” (WAS), Worked all Counties etc.
Look at the “Netlogger” for logging your nets and sharing it in near Real Time
This is merely a short list, I will keep adding to this page as time permits, for suggestions, complaints, rants etc. email me at firstname.lastname@example.org