This type of clothing spawned a category of apparel that has taken over an entire section of our wardrobes. It is the gold standard in an activewear market worth $33b in the US.
This plastic polymer is hydroponic, meaning it does not retain water very well. When it is spun into very thin threads, it becomes soft to the touch. When woven or knit into fabric, it can feel different depending on the technique. Poly can also be mixed with other materials to be softer, stretchier, or more durable.
What started as a 100% polyester microfiber shirt spawned into an entire category synonymous with sports performance. Anything from cotton to spandex to nylon, and many other materials that Nike uses and mixes can be called Dri-FIT. Not all Dri-FIT is made equal but some effort had been made to make sure that garment helps perspire better. Sometimes, it is as simple as a mesh vent.
Though Nike's Dri-FIT products are SPF30+, that's the chemical property of nearly every synthetic garment. The greatest thing you can do to prevent getting sun burned outdoors is to wear something, anything. Unless the product you're wearing directly lets light in (fishnets?) or you have a total lack of melanin, you will not be sun burned.
Nike, with its marketing prowess and stable of star athletes, pioneered the branding behind technical fabrics and activewear. There is no designer that would not want to pen a Nike line. I'm a huge fan of their work. The way they trend-set and re-innovate the brand image year-after-year is truly unique. Materials wise, every brand is juggling similar constructions in different blends.