Knits

As a sewing beginner, it is common to confuse all stretchy fabrics as being knit.
The word knit is not used to characterize the stretch of a fabric but rather a type of knitting process that creates stretch through the way the threads are interlocked and looped.

Knits are designed to be flexible, with varying degrees of stretch based on the knitting technique and not necessarily because spandex was added in the process.