What do brands mean when they say premium t-shirts?

The first T-shirt that genuinely changed something in me was a medium-sized Giordano, bought at a mall, with my own pocket money, I might add. I remember gingerly picking it up the way you pick up something you're terrified to break and carefully, with one hand, running my fingers across the t-shirt. There was a softness to it I hadn't encountered in anything I owned, which, at the time, wasn’t saying much because most of what I owned were Tantra tees from Fashion Street that had the structural integrity of a wet tissue and felt like sandpaper.