In Canada it is Inside Lane to travel in, and outside lane to travel in also..., but meant for faster moving traffic. People here do often get confused with the terminology though, so Inside lane and Outside lane is not used in the Transportation Act or any Provincial regs anymore. When I earned my driving privileges 30 years ago those terms were in use, but it now seems things have evolved and they're not in print any longer.
What is used nowadays, rather, is right lane and left lane, and sometimes depending on the number of lane ways on a particular roadway on a highway, there is sometimes any number of centre lanes in between the right lane and left lane.
The problem is a lot of motorists today think of the highway as a whole, rather than just their part of it; their roadway, which consists of all the lane ways available to them in their allowable and normal direction of travel. Looking at things from this perspective it is easy to see that the inside lane is the curb lane meant for travelling in, and the outside lane is the lane closest to the centre line of the highway, meant to be used for faster moving motorists.
The inside lane, curb lane, right lane… is for travelling, and merging onto and off of a roadway. The outside lane, fast lane, left lane… is for overtaking slower traffic which is traveling in the inside lane.
The roadways on either side of a highway sometimes have the same number of lane ways (therefore, each of the roadways on a highway would then have an inside lane for travel and an outside lane for passing), but sometimes there are odd numbers of lane ways on a highway. For instance a highway having a roadway with one lane heading north, and on the other side of the centre line, the roadway has two lanes heading south… in this case, the southbound roadway has an inside lane for travel and an outside lane for passing. The outside lane heading south is next to the double solid yellow line or median, and across the centre line is the oncoming lane heading north. That would be the inside lane for the northbound motorist, as there is only one lane heading north. If there were a dotted yellow line for the north bound motorist, a passing manoeuvre could be executed by signalling and moving into the oncoming southbound fast lane if the way were clear.
This is where the terminology makes sense. The northbound motorist doesn't have an outside lane of his own to utilize, so he must pull out of his travelling lane and move temporarily into an outside lane on the highway so that he may execute his passing manoeuvre. Since he is now travelling in an oncoming lane temporarily, he must then pull back into his own lane(the inside lane) and proceed north.
So you see, if a highway has one lane in both directions, each roadway then has an inside lane and that's it; while a highway that has 4 lane ways for example, two in each direction, each roadway then has both an inside lane for travelling in, and an outside lane for pulling out and passing. Hence, the outside lanes are the two inner most lane ways on either side of a highway, and the inside lane ways are the outer most lane ways on either side of a highway. To keep it simple though, just forget about the other roadway and focus only on your own roadway. Here in North America it would be inside lane right and outside lane left. In Britain and Ausie, it would be inside lane left and outside lane right because they're roadways are meant for driving on the opposite side of the highway to what we are accustomed to here in North America, but the idea is exactly the same. The outside lanes are next to the centre line and the inside lanes are next to the ditches no matter where you are in the world.