Are scallops and mussels the same?

I'm curious to know, are scallops and mussels one and the same? They may seem similar at first glance, but I'm interested in understanding the key differences between these two types of shellfish. Could you clarify the distinct characteristics that set them apart, such as their appearance, taste, and even their nutritional value? I'm eager to gain a deeper understanding of these aquatic delicacies.