A push payment is one of the two directions described in the entry on push vs pull payments: the payer starts the transaction by telling their own bank or wallet provider to send money to the payee. The payee does nothing except supply account details. The paying institution checks the balance before the money leaves, so a push payment cannot bounce for insufficient funds.
A wire transfer, an ACH credit such as a salary paid by direct deposit, a SEPA credit transfer and a payment over an instant scheme are all push payments. So are most payouts and disbursements, including funds pushed to a debit card through an original credit transaction.
Push payments are usually hard to reverse once sent. On instant systems they are final within seconds. This makes them cheap and certain for the payee, but it also means that a payer tricked into sending money has little recourse, a problem known as authorized push payment fraud. The main entry sets out how push and pull payments differ in authorization, risk and cost.