What's the difference between "glass" and "cup"?
For example:
-- a glass of water;
-- a cup of water.

Question

What's the difference between "glass" and "cup"?
For example:
--> a glass of water;
--> a cup of water.

Answer

A glass is usually made of glass and is primarily used for drinking cold drinks.
A cup is traditionally made of ceramics and is used primarily for drinking hot drinks like coffee or tea.  In cooking, a measuring cup is used to measure eight ounces. These days, a cup can also refer to a drink container made of plastic or styrofoam.  For example, you might ask for a "cup of water" at a fast food restaurant.

Answer

A cup is normally made of ceramics and has a handle. It is used for drinking hot drinks like tea, hot chocolate & coffee
A glass is usually made of glass and is used for drinking cold drinks water, juice, fizzy drinks.

Answer

A "glass" is made of glass (vidro?). It usually does not have a handle.

A "cup" usually has a handle.

I suggest you try a Google Images search on "cup" and "glass," you'll get the idea quickly. Or look at this image:

https://imgur.com/al5YzjI.png