Account boosting is the process of increasing the level of account, the pumping of the game personage. And this means almost anything from an ordinary upgrade of rating to an increase in the number of victories, the number of fights, quests, new weapons, and so on.
Account boosting always means that the account is given to a professional player who plays instead of a character and gains points/performs tasks for a customer. Passing an account to another person is a confidential procedure, and the security of the account is guaranteed, this is an important part of the transaction. Since professionals take the job, the boosting usually goes very quickly, and in a few days you can level up your account from zero to a very impressive level, such that an inexperienced player has to spend weeks, even months, to achieve.
In games based on battles, the professional player who is often dealed with, usually guarantee at least 70% of the victories, this indicator can be stipulated in advance, and in case of failure a client may well demand a return of part of the payment, as its conditions were not met. In games based on the passage of quests, most often specified only the number of quests that have to be passed, and timing. But the passage of quests in the game is still closer to the "game boost" term (boosting of the game), whereas "account boosting" is more associated with the pumping of the game character.
During the boosting of accounts, professional players who execute orders never use cheats, because once you get a ban for a cheating on someone else's account, no one will work with you. All the boosting is done solely at the expense of experience and skills of professionals.