In season 1 of the show Full House, Uncle Jesse is referred to as "Jesse Cochran" but later in the series he is always Jesse Katsopolis. So why the name change and is there any in-universe acknowledgment of the change?
John Stamos' character was originally named Jesse Cochran; Stamos reportedly wanted his character to better reflect his Greek heritage so producers decided to change the character's surname to Katsopolis
In terms of an explanation: In the first season, Jesse's last name was Cochran, but in the second season it was changed to Katsopolis because of John Stamos' Greek heritage. The reason for the change was addressed within the series in an episode in that the last name "Cochran" was a pseudonym Jesse was using to make his name sound more like a rock star.