A transaction service in the Microsoft Windows NT operating system that simplifies the development and deployment of server-centric applications built using COM. It's essentially a TP monitor and an object request broker (ORB) combined into an easy-to-use package.

MTS is a program that runs on an Internet or other network server with a Windows NT system and manages application and database transaction requests on behalf of a client computer user. The Transaction Server screens the user and client computer from having to formulate requests for unfamiliar database and, if necessary, forwards the requests to database servers. It also manages security, connection to other servers, and transaction integrity. The Transaction Server is Microsoft's bid to make distributed applications and data in a network relatively easy to create. It's one of a category of programs sometimes known as middleware or multi-tier programming for the enterprise market.

Microsoft Transaction Server (or MTS) is a service component that enables support for transactions to be easily implemented in other applications.