MJPEG is an older standard for video compression. First used in the mid 1990s, it is less efficient and is likely the more common standard for lower resolution video.
H.264, also known as Advanced Video Coding (AVC), was introduced in 2003 and is an efficient video compression standard commonly used for HD video (720p and 1080p) and Blu-Ray discs.
H.265, also known as High Efficiency Video Coding (HEVC), was introduced in 2013 and is the latest video compression standard to be supported by newer NVRs, especially for 4K video support. Before selecting H.265, make sure that your DVR/NVR system supports this standard.
H.265+ is an enhancement of H.265 that slightly improves the compression effectiveness. Some systems offer a separate H.265+ setting. Before selecting H.265+, make sure that your DVR/NVR system supports this setting.
Video quality
Video quality describes the level of visual detail (low, medium, high) for the video format selected. This setting can be configured on some cameras. If the setting is not available in your camera, select Medium.
Scene activity
Scene activity describes the expected level of scene activity/movement in the video being captured (high/medium/low); higher activity will result in higher capacity needed. For example, low scene activity could include a street alley or hallway, and high scene activity could include a casino floor or busy highway.