Answer:
Here are some key features to consider:
Recording modes: Continuous, motion detection, scheduled recording, etc.
Video compression: H.264, H.265, etc., to balance file size and quality.
Remote viewing: Access your cameras from anywhere through a smartphone app or web browser.
Storage capacity: Choose a DVR with enough hard drive space to store your recordings for the desired period.
Night vision: For clear surveillance even in low light conditions.
Additional features: Motion alerts, two-way audio, weatherproof cameras, etc.