What's exactly the transit area?

Hi I am a mexican citizen and I have a 22h layover in Beijing. I see I dont need a visa for the less than 24 hour layover but can I leave the city for a few hours within this time without holding a transit G type? When it says "No visa is required for less than 24 hours and do not leave the specified transit area" I dont know what you mean with "specified transit area" does it refer to NOT to leave the airport?

thanks in advance.