What is the relationship between MySQL, MariaDB, NoSQL, SQL Server, and Redis?

1, first of all, from the database type classification, MySQL, MariaDB, SQL Server These 3 kinds belong to the relational database.

NoSQL is a non-relational database and is considered a database revolutionist.

Redis becomes a memory cache database, and the previous two types of databases put data on disk, so Redis is faster.

See http://blog.csdn.net/allen_a/article/details/50611966

Http://www.cnblogs.com/weihengblogs/p/6743762.html

2. Mariadb's founder is the same group as MySQL, MySQL was acquired by Oracle, although also open source, but the pace of renewal slowed.

What is the relationship between MySQL, MariaDB, NoSQL, SQL Server, and Redis?