The infrared cannot go through walls or solid objects because it is a light wave that is limited in distance of the line of sight.
Although objects can interfere with your IR, it is very difficult to intercept or hack it from other electronic signals. It’s also very important to note that heat sources and sunlight can interfere as well since they are also using the same light waves.
The difference between IR and RF from 1000 Bulbs.com:
Check out our best IR Repeaters of 2020 review!