If you are part of the dev team like software engineer or software tester etc. you will be attached to the client company as "vendor". It is like being an orphan living in someone else house. Given lesser food and can only continue doing household chores when the family go out for an outing. Basically treated as 2nd class citizen and get lesser pay. When the whole department goes to a company event, you won't be invited. Whole office empty except your desk.