Could you explain what the 'indent' term means in Python language and why it is needed?

In Python, indentation refers to spaces or tabs at the beginning of a line that define code blocks. They are mandatory because Python uses them instead of curly braces to indicate nesting. For example, the body of a function or a conditional statement is indented:

if x > 0:
    print("Positive number")
else:
    print("Zero or negative number")

Without proper indentation, the code will not execute and will raise an error. Indentation makes the code readable and structured.