what does stack stand for code example

Example 1: what is the mean stack

Full-Stack JavaScript Using MongoDB, Express.js, Angular and Node.js

Example 2: what is full stack

1. create a data (a customer account) on UI
2. send request from API and verify data is 
matching with UI (you reach your database
through API, it is credible as much as 
your API software is credible)
3. send SQL queries using JDBC get request
to database and verify data is
matching with post request