Surya Namaskar, or Sun Salutation, is a series of postures that warms, strengthens, and aligns the entire body. It serves as an all-purpose yoga tool, kind of like a hammer that's also a saw and a screwdriver, if you can imagine such a thing.
This sequence might be considered the classic one, but there are so many variations that many modern schools would dispute this. You can alter this particular Sun Salutation by playing with its pace. If you move through the sequence rapidly (by transitioning into the next pose each time you inhale or exhale), you'll warm up fairly quickly. Start with 5 or 6 repetitions and gradually build to 12 or more or set a timer starting with 3 minutes and gradually increase to 10 or more.
Or try moving slowly and deliberately, and you'll feel how the sequence becomes a sort of moving meditation. As you practice this way, center your awareness at some point in your body (such as your third eye or your heart) and challenge yourself to keep focusing there for the duration of the practice.
Moving quickly is more stimulating, while moving slowly is more calming. Whichever way you do it, the sequence can serve as either a self-contained minipractice on days when your practice time is short or a warm-up for a longer session.
See also Troubleshoot Your Sun Salutations
Before You Begin
Warm Up: Stand in Tadasana (Mountain Pose) with your palms pressed together in Anjali Mudra (Salutation Seal). Focus for a few minutes on the inner sun at your heart, which is the microcosmic equivalent of the outer sun at the heart of our solar system. Your inner sun represents the light of consciousness, without which nothing would exist—just as our physical world wouldn't exist without the sun. This inner sun is often compared with the embodied Self, the jivatman or "liberated being." You might dedicate your practice to this light.
If Sun Salutations are your warm-up for a general practice, move slowly and consciously, gradually building heat. If Sun Salutations are your whole practice, do a 2- to 5-minute Downward Dog as a warm-up.
See also Where Did Sun Salutations Come From?