NL: Why Do You Bet And Raise?

extract value
protect your hand
get better hands to fold
attempt a semi-bluff
get worse hands to fold

they don't generate fold equity
they can be bluffed out of the pot too easily
they miss out on too many value bets
they never know where they're at

the protection bet
the semi-bluff bet
the information bet

you generate fold equity
you balance your game
you can extract value in case you hit on one of the subsequent streets
a lot of players can call you in a multi-way pot, turning the pot big
you keep the initiative on the following streets, whether you hit or don't

in order to extract value and to stop opponents from drawing cheaply
in order to get rid of weaker hands
in order to bluff calling stations out of the pot

you want to keep the initiative and generate fold equity
you want to extract value with strong hands and protect
you sometimes bet with pure air and hope to have sufficient fold equity
you always conti-bet, no matter the board or the opponent, because it allows you to balance your game

in a multi-way pot
out of position
heads-up and in position

against an aggressive opponent and out of position
against an aggressive opponent and in position
against a passive opponent and out of position
against a passive opponent and in position