ok i know it means.

กัน has many meanings depending on the context. For example, in the sentence of this picture คุยกัน (kui kan) means talk to each other - so กัน means to each other or together. Here are other examples of the usage of กัน : รักกัน (Rak kan) = Love each other, ด้วยกัน (Duay Kan) = together. Other meanings of กัน is friend (n.) (but it's rarely used) , prevent/keep out/protect (v.), trim (v.) (it's often used with eyebrows) All you have to do is just look at the context and use these kinds of words often so you will know how to use it correctly. :)