‘International Colour Consortium’ or colour profile, is a set of instructions of the main colours used in a device. It is a numerical representation of the colours in the 'colour system'. The ICC profile will translate the colours into numbers and enables different devices to interpret information similarly.
To simplify the idea of ICC profile, we need to understand why we need it, and what is the benefit of it.
If you ask several people to choose a green colour they will probably choose different shades of green, because each person would have their own reference point. But if they have one common reference to relate to, the result is more likely to be similar for all of them.
For example, if you ask them to point their finger at a green colour that resemble's WhatsApp's green, you are more likely to get answers closer to each other.
So that's what an ICC profile does. It creates reference points. When you use an ICC profile, it will help ensure the green colour is consistent across all devices that are using that ICC profile. The job of the profile is to override your screen's settings and show you what the final product will look like in real life.