Transactions are API requests that are made to the PubNub network. When you make an API call to PubNub, we count that as a transaction. Each transaction can consist of up to a 2048 byte payload. Since payloads up to 32KB are supported, larger Transactions are counted as multiple Transactions, where the payload is divided into 2048 bytes buckets. Transactions may be designated as either Replicated or Edge.