Osman is celebrating ten years as a senior Everton player this weekend.
Moyes said: "Football has evolved over the time Ossie has been around.
"Barcelona perhaps have changed things with how they've done so well with small, talented footballers - that paved the way for smaller guys to thrive in this league.
"Now there are different types of players coming into football. He could survive in the other style of football but now he is thriving.
"We're giving Ossie a new contract as he's such a valuable player."