1.What does it mean when we say that SQL is a loosely implemented language?

2.Is SQL a back-end or front-end language?

3.(Data Science) What is the purpose of EDA (Exploratory Data Analysis)?

Per wikipedia. In software engineering, the terms frontend and backend (or sometimes referred to as back end or back-end) refer to the separation of concerns between the presentation layer (frontend), and the data access layer (backend) of a piece of software, or the physical infrastructure or hardware.