In my first T-SQL Tuesday submission I thought I'd mention something that we often take for granted when working with relational databases.
At the basic level, a database table is really a relation. You can have a truly relational database with just a single table. The relationship is that between each of the attributes (or columns) with the candidate key (usually the primary key). Each attribute is dependent, in a properly normalized database, on that key, and so a single table database is still a relational database.
In the data structures I've seen over the years I've seen too many examples where multiple dependencies within a row cause problems, so it's good to revisit the basics now and then.
Enjoy the rest of your day!