A sewing label is something you sew in a piece of clothing. A long time ago a sewing label was just a simple thing stating the size of the clothing and some washing instructions.
With all the people with plenty of time at home (since Covid-19 this has been more and more so, but was already happening way before) they start with a hobby of making clothes. It can start simple with just some baby clothing, later one for your toddler or a hat for your friend, until you get to the point when you start selling your homemade stuff. Perhaps you even go as far as starting your own webshop with designer clothing. And you are good at it so you just need to focus on what you are good at, and let someone else do their own stuff. For example, these custom sewing labels you can order with your own design, logo and whatever you want from it.
Start going professional and start making your own sewing labels now.