What is the reality of worship, and does it include obedience and the entire system of life, or is it limited to ritual acts of worship such as prayer and fasting?

Worship, linguistically: submission and humility. Technically: a comprehensive term for all that Allah loves and is pleased with, in terms of apparent and hidden words and deeds. It includes both actions and abstentions, so performing acts of obedience and refraining from prohibitions are acts of worship. Worship is not limited to rituals like prayer and fasting, but encompasses all obligations, recommended acts, abstentions, and even permissible things like eating and sleeping, if the intention is to gain strength for obedience. This is based on the saying of the Prophet, peace and blessings be upon him: "And in the sexual act of one of you there is charity..." So, worship encompasses the entire system of life.