What does NSFW stand for?

NSFW stands for "Not Safe For Work"

This abbreviation also means, not suitable for work. This term shares a wider meaning rather than just one. This term is mostly used as a label or a tag before posting any content such as a video, email, or link that may carry explicit material that is inappropriate for children or teenagers.

So, such content has either sexual material or cursing, which is why it serves as a disclaimer to open it with caution, that is in the absence of a child. This content also has fixed age restrictions as well. This is carried forward under government supervision and, also by the owner of the content or the website/app, etc.

Where is this term used?

This term could be used as a tag for the purpose of disclaimer as well as it is used in the text which also has the same meaning.

For example:

Anna: I thought that the link would be spam, but it was rather an NSFW.

Elsa: Oh wow! You should avoid clicking on such links.