1. YugabyteDB：
它是开源的，云原生的和高性能的分布式SQL数据库全局分布的文档存储。 YugabyteDB旨在使应用程序敏捷。 Yugabyte总部位于加利福尼亚州森尼韦尔。 YugabyteDB作为Apache 2.0开源项目进行分发和开发。
VelocityDB：
它是一个.NET对象数据库，可以嵌入/分发并扩展为图形数据模型(VelocityGraph)。该数据库速度快且内存消耗低。 VelocityDB是一个极高性能，易于使用，可伸缩，可嵌入和可分发的对象数据库系统。
VelocityDB和YugabyteDB之间的区别：
| S.NO. | VelocityDB | YugabyteDB |
|---|---|---|
| 1 | Developed by VelocityDB Inc and initially released on 2011 . | Developed by Yugabyte Inc. and initially released on 2017 and current release on March 2020. |
| 2 | Current release of VelocityDB is 7.x | Current release date- March 2020 |
| 3 | Server operating systems of VelocityDB is Any that supports .NET | Server operating systems of YugabyteDB is Linux, OS X. |
| 4 | Its primary database model is Graph DBMS and Object oriented DBMS | Its primary database model is Relational DBMS. |
| 5 | Absence of Secondary database models in VelocityDB | Secondary database models of YugabyteDB is Document store and Wide column store |
| 6 | VelocityDB supports .Net programming languages. | YugabyteDB supports C, C#, C++, Go, Java, JavaScript (Node.js), Python, Ruby programming languages. |
| 7 | APIs and other access methods of VelocityDB is .Net | YugabyteDB supports YCQL, an SQL-based flexible-schema API with its roots in Cassandra Query Language. |
| 8 | Yes, VelocityDB has a Data Schema. | Data scheme of YugabyteDB is depending on used data model. |
| 9 | It has Implementation language-C# . | Implementation language of YugabyteDB is C and C++. |
| 10 | VelocityDB- Transaction concepts is ACID ( Atomicity, Consistency, Isolation, and Durability). | Its Transaction concepts is Distributed ACID with Serializable & Snapshot Isolation. Inspired by Google Spanner architecture. |
| 11 | Absence of Replication methods | Replication methods of YugabyteDB is based on Raft distributed consensus protocol, minimum 3 replicas for continuous availability. |
| 12 | VelocityDB has Immediate Consistency concept. | YugabyteDB has strong consistency on writes and tunable consistency on reads. |
| 13 | Sharding is a Partitioning methods of VelocityDB. | Hash and Range Sharding is a Partitioning methods of YugabyteDB. |
| 14 | It does not holds Foreign keys | It holds Foreign keys |