Escrow is a feature in Ripple users can use to send conditional payments. There're mainly two types of escrows, time-held and conditionally-held. Time-held escrows allow release payments after the specified time is passed. Conditionally-held escrows allow the release of payments when a cryptographic condition is fulfilled. However, Ripple's escrow doesn't support issued currencies—it only supports XRP.

Phoebe started a non-profit to help uneducated kids. She needs investment and approaches John, who's an investor. John agrees to invest 10,000 XRP. However, he doesn't want to release all the money at once. He wants to make an initial investment of 2,000 XRP, later release 4,000 XRP to Phoebe after three months, and finally release the remaining 4,000 XRP after six months. He can achieve this using time-held escrow.

John sends the initial investment of 2,000 XRP to Phoebe using Ripple's payment system. Phoebe can now use the money to start work on her project. She can hire people, rent an office, and so on. 

John sets up two time-held escrows on Ripple. The first escrow is set to release funds to Phoebe's account after three months. The second escrow is set to release funds after six months. John is debited with 8,000 XRP, and these two escrows will each have 4,000 XRP locked in it. 

Phoebe can be assured that she'll get funds since they are locked up in the escrow. After the first three months, Phoebe will be able to release the first escrow and redeem 4,000 XRP into her account. She'll able to release the second escrow after six months.