Signal and WhatsApp both offer end-to-end encryption but differ significantly in ownership and data practices. WhatsApp is owned by Meta, which collects metadata about user interactions, while Signal is a nonprofit that collects minimal metadata and prioritizes user privacy. WhatsApp has a more user-friendly interface with features like chat history backups, group video calls, and business tools, whereas Signal focuses on privacy with features like "Sealed Sender" to hide sender identity and options to blur faces in photos. Users prioritizing privacy may prefer Signal, but practicality depends on their contacts' app usage. Users can choose to use both apps for different types of communication.