It can be important when you can change your fate and the direction of the events of the world, and insignificant, when your actions do not affect your future, but can change, for example, the behavior of someone around you.

So in the Witcher game your choices are of great importance. Important events will determine the course of the game, opening up new opportunities, events, adventures, new people and allowing you to experience new erotic interactions. Others will lead you down a different path, where you will not have the same choices, and perhaps someone you might have befriended or made love to will become your enemy. Secondary events will give you opportunities for romantic relationships with available characters, determine their reactions to you, their behavior around you and other little things that fill the life of the protagonist.

But in any case, any choice, be it the most insignificant, will certainly have consequences. Perhaps they will not appear immediately, but they will certainly affect the fate of the protagonist. And only you decide what they will be.