Simply put, a Megapixel CCTV Camera is any camera that has a resolution of more than one million pixels.
Typically speaking any camera that offers HD CCTV resolution of 1080p HD or better is classed as a Megapixel CCTV Camera. This is because 1080p is a resolution of 1920 x 1080 pixels which is a total of 2,073,600 pixels or just over 2 Megapixels.
Currently cameras with resolutions of up to 6 Megapixels are affordable for most people looking for professional CCTV and will offer far more detail than 1080p whilst still providing the option to output at 1080p if required.
There is currently a trend towards 4k Ultra HD 2160p (UHD-1) cameras which provide a resolution of 4,096 x 2,160 which is just over 8 Megapixel although there are currently CCTV cameras available at up to 30 Megapixel.
What does all this mean for the quality of CCTV?
In order to be able to identify a number plate or face it is widely accepted that a resolution of at least 2.5 pixels per cm is required in adequate conditions (optimum angle and good lighting conditions). The higher the number of megapixels per HD CCTV Camera, the larger the area that can be viewed whilst still being able to identify an individual or number plate.
This means that you can have less cameras per installation and capture the images from further away potentially saving time on money installing costly ducting to get the cable to the camera location although as always allowing enough storage is a big factor. One 4k Camera can replace up to 26 Analogue cameras.
As an example, a 1080p HD camera can view an area approximately 9.6m across and capture enough detail to identify a face whereas a 4 Megapixel camera such as the Hikvision DS-2CD2142FWD-IS can view an area approximately 14m across.