Time controls are written as (number of moves)/(time) and if "G" is used for number of moves it means the rest of the Game. Here are some examples:
G/90 -- Each players has 90 minutes to make all their moves
G/2 -- Each player has 2 hours to make all their moves
40/2 G/60 -- Each player has 2 hours to make their first 40 moves and then an additional 60 minutes to make their remaining moves (the 60 minutes is added on to any leftover time from the first 40 moves).
30/90 20/30 -- Each player has 90 minutes for their first 30 moves and 30 minutes additional for every 20 moves after that (30 minutes is added to any remaining time at the completion of moves 30, 50, 70, etc.)
30/90 SD/1 -- SD means the same as G, it stands for Sudden Death. Each player has 90 minuts to make 30 moves and then an additional 1 hour to finish the game.
G/5 -- Each player has 5 minutes to make all his moves
Some time controls have either increment or delay. An increment is added to your time at the end of each move. For example, the time control G/90+30 means you start with 90 minutes and your time increases 30 seconds each time you move, this is all the time you get for the game. For delay, your clock does not begin to run as soon as it is your move, instead it begins to run some amount of time after your move starts. A 5 second delay is typical. It's not generally written in the time control and usually the first time control is decreased by 5 minutes to compensate for the extra length (since often in tournaments not all clocks will have the delay feature and some games will use it while others won't).
why can't that be 2 mins?
d10 means there is a 10 sec delay before the clock starts