@jan_mazurek In simple terms, UX Writing is the text you see while you are interacting with a product or a service (error messages, 404, actions). Crafting emailers are also becoming the job of a UX Writer, since from there as well the user interacts with a product.
@rashikaahuja it's also way to show text in proper way
It defitelly has impact on how application / website / brand is perceived.
Eg when I get error messages must be as clear as possible in order that user could know what was done not well and be able to continue with a process
For sure and this is becoming an increasingly important topic when building even startups. If you want to seem playful, fun, childish you can for example use Comic sans to create that perception. While the words that you use to describe an error will be completely different between a bank and producthunt, because they stand for something different, have different target users etc.
@alexbthomsen Right, we need not sound playful in every message; it just needs to be clear and keep the user informed about the reaction to their action. I follow a lady who has written a great book on Microcopies- Kinneret Yifrah.