a baffle is any object or component whose purpose is to divert, or otherwise control the flow of anything.

For example, a baffle in an [[OpenValley open valley]] may be placed to divert the flow of water, preventing it from splashing back up underneath the shingles.

Baffle plates or screens may be placed or suspended in a room to control and dampen sound.

Baffle elements may be used in a lighting system to diffuse or otherwise control light distribution.