What does it mean when we say that SQL is a loosely implemented language? Is SQL a back-end or front-end language? What is the purpose of EDA (Exploratory Data Analysis)?

Software engineering

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)?