P2PKH (Pay-to-PubKey-Hash) inputs and outputs have been used since the early days of Bitcoin. For a long time P2PKH was the most commonly used input and output type. Since the activation of SegWit, P2PKH is slowly being replaced by their SegWit counter parts. The SegWit counter parts take up less weight (i.e. space) in the block and thus require lower transaction fees.
More information about P2PKH can be found on learnmeabitcoin.com.