Once a novice player becomes comfortable working with hard and soft hands in blackjack, the next part of their blackjack strategy to work on is pair splitting.
Kind of like how soft hands require a little extra thought to play at first, so too do pairs in blackjack. The biggest trap in dealing with a pair is the just knowing that it is a pair, and that you have an extra playing option that is not available with hands that are not pairs.
Because of having this extra playing option to split a pair into two new hands and possibly win twice as much in a single round, players make the mistake of splitting every pair. Unfortunately this is not good blackjack strategy.
Just because it is a power and the player has the power to split it does not mean that every pair should be split.
For example a pair of 5s and a pair of 10s should not be split. The pair of 5s can be played like a hard 10 and be doubled down on. Doubling on a pair of 5s has better odds of winning and making a profit than splitting the 5s does. Likewise, a pair of 10s is stronger as a hard 20 than split. This is because there are only two hands with which the dealer can beat you with: hitting to 21 or having a natural blackjack.
But then there are pairs that should always be split simply because the player has a better chance of building two stronger hands than beating the dealer by standing on the pairs. Those two pairs are a pair of Aces and a pair of 8s. It is more advantageous to split those two pairs.
Basic strategy is a good pair splitting strategy tool. It should be used as the base of your blackjack strategy because it tells players the most advantageous play to make.