Yoga Practice and Philosophy includes many things.
"Yoga is ideal for connecting the body mind though a process and practice that gradually benefits our ability to concentrate and become independent. We improve our health, our relationships, and everything we do." (page 13 Heart of Yoga)
Yoga practice consists of three elements tapas, svadyaya and isvarapranidhana.
Tapas is to "heat" or "cleanse" , a way to keep ourselves healthy and to cleanse ourselves inwardly. This is the practice of Asana and Pranayama, that is physical and breathing exercises of Yoga. Asana literally means pose or place.
Svadyaya literally translates "self", "study" or "investigation". This is the study of ourselves, who we are, what we are and what is our relationship to the world.
Isvarapranidhana is a "love of god" and a certain quality of action!
While these are general definitions these terms are discussed in the Yoga Sutra of Pantanjali and can be contemplated in many ways.
Together these terms are known as Kriya Yoga, which is one branch of Yoga that can lead to a change for the better in all aspects of our lives!