Your eSIM connects to Vodafone and Türk Telekom. These are two of the three big carriers in Turkey, and together they cover almost the whole country. Your phone picks whichever one is stronger wherever you are, so you do not have to choose or switch anything by hand.
Vodafone tends to be strong in the cities and along the Aegean and Mediterranean coast. Türk Telekom has wide reach too and holds up well in towns and along main roads. Having both on one eSIM means if one network is weak in a spot, your phone can lean on the other.