For example, if a DAO wanted to hold a quarterly vote to distribute some of its treasury among community projects, then it would create a new pool each quarter. Projects, represented by profiles in the registry, apply to receive funding from the quarterly pool. The allocation strategy determines who is eligible to receive funding, who can vote, and how funds are allocated and distributed and offers a lot of freedom to strategy writers for how to implement these things.
If the DAO uses Quadratic Funding, like Gitcoin's Grants Program, then members of the DAO donate to the projects they want to support. Each donation is also a 'vote' for how much of the pool that project should receive. When voting is finished, the pool distribution is calculated and then distributed to recipients.