What is the Difference Between an API and Microservice
Trying to compare the difference between APIs and microservices is a bit misleading because APIs are actually an essential part of a microservice architecture. Each microservice in the architecture will have its own API. The API sits in front of the microservice and allows communication between the different components of the microservice architecture. A microservice architecture likely contains many APIs, though APIs can also be used for other purposes without being a part of a microservice architecture. This is likely where the confusion comes from when comparing the two.
It can also be confusing because APIs and microservices can seem to accomplish similar goals. For example, if you could use an email API in your application like SendGrid to deliver emails. Alternatively, it is also possible to have an email service within a microservice architecture.