Azure service to create consistent and modern API gateways for existing backend services

Pricing Tiers: Consumption, Developer, Basic, Standard, Premium, Isolated
Cache Types: Internal, External (Azure Cache for Redis)

Versions: Separates APIs with breaking changes
Revisions: Provides minor non-breaking changes to API

API Management Components

API Gateway
Accepts API calls and routes them to your backend
API Gateway also provides the ability to verify API Keys, JWT Tokens and other credentials
Allows to enforce usage quotes and rate limiting
Provides caching for backend services

Azure Portal
The administrative interface where you set up your API program
Set up policies like quotes and perform transformations on APIs

Developer Portal
Web user interface for developers where they can read the API documentation
Try out API using Interactive Console

Product and Groups

Products
Defines how APIs are surfaced to the developers
Can be Open or Protected. Protected APIs must be subscribed to before being used

Starter: No Admin Approval Required. Allows 5 requests per minute up to 100 requests per week
Unlimited: Admin Approval Required. No Rate limiting present

Groups
Allows to manage the visibility of products to developers
Admins, Developers and Guests are the three built-in groups

API Management Policies

Collection of rules that can be executed sequentially on the request or response of an API
It can be used to perform various operations like: converting data from XML to JSON, checking existence of headers and setting cache configuration
Policies can be applied at the Global, Product, API and Operation scopes
They are defined using XML

Policy Types: Restrictive, Advanced, Transformation, Caching