In the world of Elections, Central Count has a specific meaning. Central Count is where ballots are counted from vote by mail and other ballot collections such as provisional ballots that don't fit with the system. They may or may not fit the rules - they are "provisional"). Some Counties have "Satellite Voting" where polls are open at earlier dates than election day and held to be counted. These ballots are taken to a central location to be counted - a "Central Count."
The workers that staff Central Counts are better trained (usually) and must count ballots at a higher speed. Additionally, the risks are higher for error or fraud because there are many more ballots and the ballots are not being handled by the voters themselves.
There are many tasks, all operating in parallel, occurring at central count facilities. Ballots coming in must be checked for eligibility, signatures verified, the ballots opened, the ballots examined for physical damage and then gathered into batches and then counted on high speed optical counters.