Sometimes, the Azure credit included in different subscriptions is enough for our development tasks. However, in other cases, we don't want to spend Azure credits or be billed for our development tasks that use Cosmos DB storage and services.
Microsoft provides the Azure Cosmos DB Emulator, which we can install on specific Windows versions, that emulates the Cosmos DB service without working with an Azure subscription or any other Azure service. The Azure Cosmos DB Emulator runs as an application that uses resources in the computer on which it is installed, and therefore makes it possible to perform many Cosmos DB operations and tests without incurring any Azure costs.