yearly or annual
What's the difference between annual and yearly?

Question

Answer

"Annual" is an adjective.  "Yearly" can be an adjective or an adverb.  Both pertain to a year.

Examples:
Our annual picnic will be on Saturday. (adjective)
I attend the picnic annually.  (adverb)

Our yearly picnic will be on Saturday.  (adjective)
The picnic happens yearly.  (adverb)

Answer

They mean the same thing but annual can be a little more professional.