Cursors are not the best solution when talking about performance but,

If you run into issues with another coding technique and need to get something done quickly, using a cursor may be a viable alternative. It may take longer to process the data, but the coding time might be much less. If you have a one-time process or nightly processing, this could do the trick.

This article contains a good description, example and alternatives to cursors.

https://www.mssqltips.com/sqlservertip/1599/sql-server-cursor-example/