What is code block ?

Answer 1

It is a wholesome logical piece of code, for example all set of instructions under an if statement or a for loop is considered a code block.
In Python, correct indentation of code blocks is vital to proper code flow.

Answer 2

code block is code that will be executed

Answer 3

In Python all the indented stuff following a line that ends in a colon is a code block.

Answer 4

Code block is just bunch of statements wrap inside curly braces.

Examples :

Functions.
Loops.
Logical Statement.

Answer 5

Indented lines under a function or module

Answer 6

In most modern language, a code block is a number of lines of code delimited by curly braces { }
In python, indentation is used instead.

You can have nested blocks, ie blocks within blocks.
(e.g., an if statement in a function)

in languages like java or c++, the scope of a variable defined within a block is limited to the block. The variable is not recognised outside of the block.

there is a good explanation here:
https://en.m.wikipedia.org/wiki/Block_(programming)

Happy coding!