IFR (“Instrument Flying Rules”) rating, also known in Europe as IR (“Instrument Rating”), is an addition to your pilot license that allows you to fly airplane without outside visual reference. Basically, in clouds.

Because instrument flying is so different from visual flying, it is not included in the basic pilot license, not even commercial. It is a separate set of knowledge and skills that you are expected to have to be in this, quite hostile, environment.
What are the risks of the instrument flying, and why do i need special training for it? First of all, it is the disorientation. An average life expectancy of a non instrument trained pilots getting into a cloud is about 178 seconds! It basically starts with the VFR habit of believing what you see and what you feel, the following disorientation, stall, spin or spiral dive, and the hard contact with firm ground that follos. For this reason, Transport Canada requires a minimum 5 hours of instrument training for private pilots. It is not to fly INTENTIONALLY in clouds. But to get out of a cloud safely, shall the pilots inadvertently get into one.
Second, without seeing outside of the cockpit, it’s not easy to know where you are and where to go. Even if you manage not to spin into the ground below, how do you avoid the terrain at your level? Canadian prairies are more forgiving. IFR on Canadian West Coast is an extremely short adventure if you are not 200% sure where the mountains are. So you need to learn to use and interpret navigation instruments, from wherever you are, up until the moment you touch down at the threshold of the runway at the destination airport.
This said, what does it take to get those very special skills? Transport Canada requires the following: