A question, how can I modify

Both texture dimensions are set to Power of 2 where applicable
It’s highly recommended that all textures are a Power of 2.

My product has a feedback. This problem arises, I need to modify him, but my English is very bad, I can’t understand the meaning of this feedback, request detailed explanation.

Am I going to change the texture size to a format like 1024X1024 2048X2048 4096X4096?