Basic strategy is the mathematically correct way to play every combination of hands you can get.
It can be learned by memorizing 28 simple phrases. Any advantage play for blackjack is founded on basic strategy, without it you are wasting your time and money.
Example: My hand has a total of "9"
Phrase is "double down 3 thru 6, otherwise hit"
Now you know the correct play for all conditions when you have a hand that totals 9.