Infrared cameras & thermal imaging cameras are almost same thing however there is a little difference present in background but even that is confused sometimes. Basically, both infrared cameras & thermal imaging cameras lie in the category of thermographic cameras. While they can be used in a lot of the same settings these cameras are also used in different capacities as well.
Difference between both Cameras
You can think of this difference as application of Hess law, if you ever studied chemistry. In a less confusing way, regardless of the path taken to render the body you get same result on display. As you can judge by the name of infrared cameras, they make use of infrared photons emitted by various bodies to give you a picture of whats going on when a human eye cannot see. Whereas, think of a thermal imaging camera, you can clearly see by name that they make use of thermal energy. They dont render the photons directly but instead they make use of the temperature change in surroundings. So you can say that thermal imaging cameras absorbs the thermal radiation emitted from a body and displays that to you in an image.
For the processing and display part of the equation, if you consider the processing then their processing of the input will differ because processors will get different input. When it comes to output or delivering the image/video its same actually. You will get the output in the form of a grayscale sketch where the difference between thermal or infrared densities of bodies will determine the difference of color density. So it is pretty clear that whatever way you adopt you will land on same output. However there are some conditions where one way is more viable than other which is something you want to be on the lookout for.
You must have witnessed the usage of either infrared camera or thermal imaging camera in movies. Cant recall? May be you dont know the fact but most of the times you see a sort of colored output in movies it is as a result of thermal imaging. Yes, the actual output is grayscale in theme but false color themes are added on to get a more distinguished view. For instance, different colors can be associated with different color densities and in the end you will get a reddish, yellowish and greenish sort of output. These are witnessed in movies and other parts of society as well so if you have seen this effect other places that is totally natural as well.
Infrared cameras & thermal imaging cameras are not much useful in daily life. However these cameras are of immense importance when it comes to military, police or firefighters. There are endless uses of these cameras and these cameras can become lifesavers when used in these emergency situations.