Definitions for "Basic Strategy"
A playing strategy sometimes referred to as perfect play, that is designed to minimize the house edge without counting cards.
A method of that is geared toward improving the player's chances of winning a single hand. Since the likely outcome of every decision (hit, stand, double, split, or surrender) in every possible situation (every possible value of the player's hand versus every possible dealer's upcard) has been proven mathematically, there is currently only one "basic strategy."
In blackjack, the set of plays that you should make to maximise your advantage.