Traditionally, enterprises relied on a unified model for designing a software application. Here, key capabilities for managing input/output processing, error-handling, and UI are packaged into one monolithic process. In such a structure, all the application components are interconnected and interdependent.
Such a structure, however, limited the scope for an application to expand and scale. This is when microservices came into the picture. Here, a single monolithic system is broken down into a set of smaller services, carrying out a functionality in a distributed manner. Its loosely coupled structure enabled enterprises to add or iterate any component of an application independently. This gave scope for scaling and expansion at a much faster rate.