These strains can be sorted into three broad categories, sativa, indica, and hybrids. Which one you choose will depend on personal preference and desired effects.
The sativa plant originated in countries close to the equator such as Thailand, Colombia and Mexico and it thrives in warmer environments. Sativa gives more of what is called a “head high.” Sativa tends to have a higher THC:CBD ratio. Some potential benefits of using THC are boosted energy, creativity, and focus. Medicinally Sativa can be used to fight depression, help alleviate some of the symptoms of ADHD, and stimulate appetite. Since Sativa can have a stimulating effect, it is best used in the day time or during social situations.
The indica plant originated in cooler climates such as the mountainous regions in middle east, and it is a shorter bushy plant. Indica has more of a “body high,” and tends to have a higher CBD:THC. This can provide many benefits including pain relief, muscle relaxants, and sleep aid. Medicinally indica can be used to treat migraines, headaches, insomnia, nausea, and anxiety. Since indica can have a relaxing effect, it is best used in the evenings or on a day when you don’t have much to do.
There are a wide range of strains which are a mix between sativa and indica plants, and they provide a mix of the benefits from both plants. Many of these strains are labeled ID (indica dominant) or SD (sativa dominant). An indica dominant strain will have more the effects and benefits of indica, and sativa dominant strain will have more of the effects and benefits of sativa.
Different strains have different concentrations of THC and CBD. If you are a medical cannabis patient, or if you simply prefer CBD to THC you may wish to select a CBD dominant strain.
For more information on selecting strains check out one of my favorite cannabis resources Leafly.