➦   The main difference between 4K, 2K, 2 megapixels, and 720p resolutions in security cameras is the level of detail and clarity in the video footage they provide, with higher resolutions offering greater image quality.

➦   4K is the highest resolution, followed by 2K, 2 megapixels, and 720p, in descending order of image quality.
➦   The choice of resolution depends on the specific surveillance requirements, budget, and desired level of image quality for the intended application.