SMTP (Simple Mail Transfer Protocol) and POP (Post Office Protocol) are email protocols with distinct purposes: SMTP (Sending): Used for sending outgoing emails. Transfers messages from a client to a server or between servers. Facilitates communication between email servers. Works in the background during email transmission. POP (Receiving): Used for receiving incoming emails. Retrieves messages from a server to a client. Usually deletes messages from the server after retrieval. Enables offline access to received emails. In essence, SMTP focuses on sending, while POP focuses on receiving and downloading emails to local clients.