Sprite renderer or mesh renderer

Hi, i developing a 2D RPG game now and need some advice for showing image when doing dialogue (Like a JRPG one or a visual novel). For now I'm using sprite and sprite renderer to display the image and the dialogue box. After i was showed some similiar game by my friend, most of the image is displayed using mesh renderer.

Is there some big difference between using the two of them? Any pro and cons?