Yes. In Av mode you choose the aperture and the camera sets the shutter speed; in Tv you choose the shutter speed and the camera sets the aperture. The main benefit is speed and convenience: the camera handles standard exposure while you control the setting that matters most creatively.

Use Av when depth of field is your priority, such as landscapes or tripod shots where a long shutter speed is acceptable. Use Tv when motion is the priority, such as keeping shutter speed high enough to freeze action or avoid blur with a telephoto lens.

Compared with full Auto/Program, Av and Tv give you more control over the look of the image, because different aperture/shutter combinations can give the same exposure but very different results.

Manual mode is best when you want complete control, have time to set everything yourself, or need exposure to stay consistent from shot to shot. The tradeoff is that it requires more attention and is slower to adjust.

In short: Av/Tv are useful when you want creative control without having to set every exposure variable yourself.