What does "Specified Transit Area" means?

"No visa is required for foreigners who hold tickets to the final destination and have booked seats on international airlines, ships, trains transiting directly through China, and will stay for less than 24 hours and do not leave the specified transit area."

What does "specified transit area" mean? I will reach Beijing airport and need to collect luggage and take another flight to Khabarovsk. So I have to go through custom and check -in again. So is it still valid the direct transit within 24 hours?