Learning is forming (in neural circuits, in silicon, ...) an internal model of the world. Here are some examples:
Mental map of the neighbourhood.How actions on pedals and handlebars affect the stability of a bike.Label the event of two bees spontaneously recombining into a hummingbird incredibly improbable.Model of the English language.Mental model of your cousin Cossandra: appearance, voice, tastes, quirks, ....If an aspect of reality that is not yet modelled is experienced, than our brains will try to model it. This is one aspect of learning.
The new model could be internal to the body, e.g. playing violin.The new model could be a reflection of external reality, e.g. mapping a new neighbourhood or learning Statistics.