Insert data into newly added column of existing table in SQL Server

Hi there,

I have a database with multiple columns and rows, and recently I opened a new column name which I would like to insert categorical values inside, i.e. if column "description" has values inside like "groceries" then insert values "essentials" in column "Main_Category" Something like this.

I googled but could not figure it out how to do it.

Any help is much appreciated.

Best Regards,

E