What does it mean to bet on value? And bet on protection?
A greeting!

Bet on value means that you have a strong hand and you expect your opponent to make a call with second or worse pair, or the same pair with worse kicker
Bet on protection when you bet with strong hand(like pair) but your hand is vulnerable, like there is 1 card that complete 4 cards straigh or brings flush or you have pair or 7 and easily any higher card may be scary for you, so you don't want your opponent have the right price to chase it and make protection bets bigger sizes

We bet on value with a strong combination or a hand of all kinds to make a profit, but at the same time we are afraid to lose, because when the cards come out, our strong combination can be outbid