In this paper, the authors have done a comparison between the leading database systems currently used in industry as well as in academics. Relational & Non-relational are the two leading Databases currently used in both academic & professional industry. Database stores data, which generates rapidly these days, but database is not only about storage information. Database is also concerned about managing huge mass of data in a consistent & stable manner, which is also quickly recoverable or accessible when it is needed. The prominent features of both the databases with all specifications & comparisons are analyzed here. Relational databases are around us for so many years and are a choice of most technologies, but current growth of data and the internet market with the new emerging of web technologies leads us toward new trends like web 3.0. These technologies is new, leading us to a new challenge & management concept. NoSQL database, has become a very popular database, because it gives us an alternative to the relational database especially in dealing with massive data. As we already know, this is a main problem of DB management with high availability & scalability for distributed systems as they need fast access with no down time during problems. This paper present the concept of Non-relational database motivations & movement, and the needs behind it and also reviews the different types of Non-RDBMS and the issues related to both databases with application & security issues and their comparison with relational databases.