Difference between “etwas zu trinken” and “etwas trinken”

Question

I would like to know the difference between the following two sentences:

Ich möchte etwas zu trinken.

Ich möchte etwas trinken.

Answer 1

Maybe the difference is best explained by translating both sentences:

Ich möchte etwas zu trinken:
I would like something to drink.

The person is stating, that he/she desires the object (or rather: liquid) he/she wants to drink. Note that you could also use etwas zum Trinken.

Ich möchte etwas trinken:
I would like to drink something.

This case emphasises the action of drinking.

Usually, both versions can be used interchangeably, although I would say the first one is more common, especially in situations discussing the act of buying food/drink (the object), like in a restaurant. In contrast, Ich möchte etwas trinken would be a way to tell that you are generally thirsty, and need to drink something (in this case the drinking is more important).