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HTML Exercises Many chapters in this tutorial end with an exercise where you can check your level of knowledge.

SQL Tutorial SQL is a standard language for storing, manipulating and retrieving data in databases.

Python Exercises Many chapters in this tutorial end with an exercise where you can check your level of knowledge.

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This tutorial follows Bootstrap 3, which was released in 2013. However, we also cover newer versions; Bootstrap 4 (released 2018) and Bootstrap 5 (released 2021).

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C# Exercises Many chapters in this tutorial end with an exercise where you can check your level of knowledge.

The box-sizing property allows us to include the padding and border in the box's total width (and height), making sure that the padding stays inside of the box and that it does not break. You can read more …