Have a look at this and this for a short intro what a NoIR camera is. NoIR stands for No Infra Red filter meaning the sensor will pickup IR waves in addition to visible light which will affect the final image.

- image referenced from here, (disclaimer: photo copyright belongs to the owner)
If you need to monitor both during day and night, you'd probably have to go with 2 cameras - one that works with the IR filter for day and one without IR filter for night. as seen in the above image NoIR might not give usable results during day depending how much ambient IR is around. Since the images from the filtered (day camera) and unfiltered (night camera) will look different, I'd think you will need different algorithms for each camera to detect and identify objects in the images.
Here is pretty good documentation on the camera module and how to use it from python