Skill Point

A is a sum of experience points that can be spent on a Skill at a Shrine.

Experience Points
Progress towards your next can be viewed around the edge of a respective Shrine's skill deck (left of where you place your hand). You'll see light-blue markers for your skill points, and a larger blue ring for your progress towards your next point. There is also a special shrine behind the Town Hall near the mountain pass which shows all professions and their respective experience points.

Upon unlocking the next however, a large effect plays around the player, informing that a new  can be spent.

Experience points can not currently be lost (other than through spending).

You'll know when you've gained a Skill Point while performing a related task; you'll hear a sound akin to a chime and orange streaks of light will circle your character, momentarily.

You can only carry 3 unspent Skill Points at a given time, and can only allocate 8 Skill Points total. This means you should take care in allocating your points, preferring to max a Skill Tree in one class than to dilute your points across lower skills of multiple classes.