what do apple watch icons mean

Are you asking about the icons on Apple Watch Faces? If yes, they are called complications and allow you to tap them to see things like weather, battery percentage, email, messages etc.

If this is what you are asking about, this link will help you --> Apple Watch faces and their features - Apple Support

Do you mean the images for the different apps. If you are unsure you can change that in settings to be a list instead which will give you all the names.