Wikipedia describes the higher self as “a term associated with multiple belief systems, but its basic premise describes an eternal, omnipotent, conscious, and intelligent being, who is one’s real self.”
You might think of the Higher Self as the bigger part of you that is more connected with the whole of the Universe. It knows the stars, it knows the cosmos, it knows the angels; it knows that it is directly a part of God/Source.
An easy analogy would be to compare the parts of our human lives that we tend to compartmentalize, such as work, activities, friend groups and even family.
You might have quite a different way of experiencing and operating in your work environment compared to, say, your home. You as your “work self” might be more cautious to take action in a certain area or to embrace a new idea, due to the agreements you have with your employer regarding your job description and pay. You as your “home self” may, however, love any and all changes in routine and be thrilled at the chance to explore the unknown and try something completely new (or, on the flip side, you might be even more cautious because of an agreement to support a partner or the responsibility of caring for children).
In this example, you can think of the Higher Self as your essence — the aspect of you that is always the same, whether at work, home, or out with friends, and which has not compartmentalized itself to fit a particular situation.