Updated: Oct 27, 2021
I think it's easy to fall into one of two categories when first approaching yoga, one being "isn't all yoga just kind of the same" and the other "oh they all seem to have different names and there's so many styles, where am I supposed to start". Whether you're overwhelmed with information or have no information at all this article should provide a brief overview of some of the most popular styles of yoga.
Although initially an umbrella term simply referring to any system that pairs breathwork with series' of poses, it has taken on the definition of a fluid slow paced, more meditative class with medium length holds. Whilst being a slower style there can still be an element of flow. A beginner hatha flow is a great place to start for all ages and abilities.
Ashtanga and Vinyasa
Ashtanga yoga is a fast paced and demanding style of yoga that was created to be aimed at stronger more energetic yoga students. It does have some techniques associated with it such as a certain type of breathwork (pranayama) and particular types of body locks whereas Vinyasa is like a freestyle version of these techniques and flows. A full ashtanga class is long (usually around 90 minutes) and challenging, some might even say arduous, but as is the case with many challenges it is equally rewarding.
Although similar to (and sometimes used interchangeably with) Ashtanga and Vinyasa. Power yoga is more like Vinyasa as a more freeform style. As could be guessed by it's name, power yoga is more strength orientated, usually made up of short holds and dynamic stretches. Typically it's characterised by almost constant movement/work and sometimes incorporating multiple postures.
Unlike Hatha, Yin yoga has no real element of flow. It's aim is almost purely recovery but obviously has some utility as flexibility work. More akin to a self administered deep tissue massage it involves long passive holds of just a few poses. you can expect to be in these poses for up to 5 minutes. While not being as much of a calorie burn, yin yoga can be challenging mentally and physically especially if you're attempting a new pose.
Commonly known "Hot yoga" and named after it's founder Bikram Choudhry (see Netflix documentary 'Bikram'). It is a specific sequence of 26 poses (24 asanas/postures and 2 pranayama/breathing exercises) performed in a room set at 41 degrees centigrade and a 40% humidity. These classes are around 90 minutes long and are (as you might have gathered) very challenging. Needless to say if your really looking to work up a sweat then this could be exactly what you're looking for.
There are endless niches of yoga practice to explore, some I have tried such as acro-yoga (yoga with a partner) and yoga-pump (a yoga/body-pump hybrid), and some I haven't like Kundalini yoga (a style influenced by tantra). So explore and have fun with it!