"YW" is an abbreviation for "you're welcome. " It's a quick and nice way to reply when someone appreciates you via text messages or in online chats. Rather than writing the entire phrase, everyone just use "YW" to be quick and keep the talks easy-going. This term is very much used on social media, messaging apps, and gaming chats. Even though it is informal, it is still polite and very well recognized. Nonetheless, in more official circumstances, like emails or professional conversations, it is better to spell out "you're welcome" as this will make the message sound more respectful and clear.