The term outside or inside spin (or english) tends to confuse many beginners who are accustomed to side spin being referred to as left or right english.
The illustration shows "inside" and "outside" angles. Outside english is a hit on the cue ball whereby the tip hits the cue outside the angle (in this case, right.) Inside english in the illustration would be left english.
The "angle" is created by the cue ball's path to the object ball as it relates to the object ball's path to the pocket.
Outside english is also considered "natural" english, because it is the spin that would otherwise be imparted to the cue ball by friction with the object ball. Outside english can be used to compensate for directional throw* since it allows the cue ball to "roll" off the object ball on a path outside the angle.
The terms right and left english do not relate to the angle to the pocket, whereby the terms outside and inside directly relate.
* When the cue ball contacts an object ball, the object ball is "pushed" slightly forward before "bouncing" off the cue ball. This anomaly is called "throw".
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