currency

I'm off to Icmeler in July, this will be my first time in Turkey, I am very excited but totally confused by the whole which currency to take thing! I have read that they do like sterling over there, does that mean in a restaurant they give you a bill in stirling or is it in lira and i would need to convert it to give them money in sterling
also at the market do they barter in sterling or lira. I am completely confused
also at the market do they barter in sterling or lira. I am completely confused
