What is the difference between Web-to-Case and Email-to-Case?

Web-to-Case generates an HTML form that customers fill out on a website; on submission, Salesforce creates a case directly from the form data. Email-to-Case creates a case from an inbound email sent to a designated email address. On-Demand Email-to-Case uses a Salesforce-managed forwarding address — no local agent is required. Standard Email-to-Case requires a local agent installed behind the firewall to download emails via POP3/IMAP. Both methods support auto-response rules and can trigger assignment rules on case creation.