Definition of pot
By pot, we mean "jackpot". The money that players play for in each poker hand is called a pot. In online poker rooms, when you want to use shortcuts to make your bets, you will see "50% pot", "75% pot", "pot". This is a very common way of thinking to orient the size of your bets according to the size of the pot. Each pot will play differently depending on its size. A bluff wouldn't carry any weight if you bet 5% of the size of the pot to bluff. When playing a poker hand, always keep the size of the pot in mind.
Some generalities about the different sizes of pot
People will bluff more often in the big pots. Also, the hand that wins a big pot will often be stronger than the hand that wins a small pot. If several players are fighting for the same pot, you will need to have a very strong hand to be part of the battle. Usually when players make "overbet pot's" (make a bet that is bigger than the size of the pot), they will be polarized; part of the time they will have a very strong hand and part of the time they will have a bluff.