Get all selected tableviewrows in tableview?

I got really confused by the following terms and functions:

• TableView: function selectRow(row): void & function deselectedRow(row): void
• TableViewRow: function getHasChecked(): boolean & function setHasChecked(boolean)

My questions are:

1. How does the above two things differ? What property does tableview select function changes?
2. If there are select and deselect functions in TableView, does it have a function that can keep track of all the rows I can selected, for example a function like "getSelectedRow"? Or do I need to iterate over all tableViewRows to get the status? If so, which property should I check for each row?
3. I saw that people mentioned something called "row.hasCheck" in other Q&A questions, is that a custom defined property or is that a property that every row originally has? If it is something that row has, how is that different from the value returned by getHasChecked function?

Thanks so much for help in advance, I really need someone help me clear my mind for these ideas...