Can anyone explain to me what is going on between direct line planning, dedicated line planning, direct customers, and group agencies in travel agencies? How do they operate during tourism?

For example, for a travel agency in Qingdao, linear planning is responsible for designing travel routes in Qingdao. Special line planning is to design the entire route in the peninsula or Shandong, and then inform the travel agencies in other places. It's called peer sales. This out-of-town travel agency thinks this route is good, so it collects guests who want to go to Qingdao. This is called direct customer sales. When a certain number of guests reach a certain number, they form a team and send them to Qingdao. This out-of-town travel agency is called a group agency, a travel agency in Qingdao. It’s called Dijieshe