Raw fish is one of the traditional ingredients in sushi but sushi may also be made without meat or with cooked seafood as long as it uses vinegared rice. Sashimi, on the other hand, always contains fresh raw meat or seafood.

Source https://www.diffen.com/difference/Sashimi_vs_Sushi#:~:text=Raw%20fish%20is%20one%20of,fresh%20raw%20meat%20or%20seafood.