A static cursor always displays the result set as it was when the cursor was opened. Static cursors are always read-only.
Dynamic cursors are the opposite of static cursors. Dynamic cursors reflect all changes made to the rows in their result set when scrolling through the cursor.
A forward-only cursor does not support scrolling; it supports only fetching the rows serially from the start to the end of the cursor.
The keyset is the set of the key values from all the rows that qualified for the SELECT statement at the time the cursor was opened