How to make bold and italicize text in Markdown?

Suppose you want to bold and italicize text simultaneously. In that case, you have to type three asterisks or underscores before and after the text. By doing this, you will get the bold and italic text.

Markdown HTML Output
This is a ***bold and italic text.*** This is a <strong><em>bold and italic text.</strong></em>
This is a ___bold and italic text.___ This is a <strong><em>bold and italic text.</strong></em>
This is a **_bold and italic text._** This is a <strong><em>bold and italic text.</strong></em>
This is a __*bold and italic text.*__ This is a <strong><em>bold and italic text.</strong></em>

Note: For compatibility issues, it is recommended that you use asterisks instead of underscores for making bold and italic text.