The act of restricting the sale of a token for a particular period of time.
Vesting period, also called the token lockup period, refers to a period in which tokens sold in the pre-sale ICO stage and offered to partners and project team members as incentives for their contribution are prevented from being sold for a specific period. A vesting schedule is announced by the project to release these tokens at intervals throughout a given period.
A healthy token economy requires that most tokens are held by investors and not released into the market. Locking up tokens allows the team to prevent the value of their token from dumping. It also disables the team members to sell their tokens right after the trading goes live, hence, protecting the interest of the holders.
By locking up tokens, projects prevent dumpers from crashing the price as soon as the token gets listed on any exchange. It is usually a part of their anti-dump policy to attract more investors by gaining their trust in the longevity of the project.