A Founder's Vesting Agreement is a contractual document that outlines the terms and conditions of a founder's ownership stake in a company. This agreement outlines the vesting timeline for the shares owned by the founder, the release of the shares, and the vesting restrictions if the founder leaves the company. There are two types of Founder's Vesting Agreements: Time-Based and Performance-Based. In a Time-Based Vesting Agreement, the founder's ownership stake is released over a fixed period of time, determined by the company. In a Performance-Based Vesting Agreement, the founder's ownership stake is released based on the company's performance goals, such as hitting certain revenue targets or achieving certain milestones. Both types of agreements are designed to ensure that founders are rewarded for their contributions to the company and incentivized to remain with the company for an extended period of time.