APIs have made it much easier to interact with other applications with codes (your app) like fetching data, updating contents and adding new. Practical Use of API 1. Social Connect (eg facebook like, comments) 2. Database transfer (e.g surveymonkey to google sheet) 3. Lead Genaration (e.g gathering phone numbers and emails) 4. Product data (e.g getting products images, description by GTIN) Many other