Why whe can show text just with <p> without closing tags at html

Question

Wanna ask,why when we delete the </p>

at

<p>This is a paragraph

It still can display the text

Answer 1

End tags are used in HTML/XML to define scope: to demarcate where the content of a node begins and ends. All languages have some way of defining scope: it's a crucial aspect of parsing, because all the browser is seeing is one character at a time.

Answer 2

XML is different than HTML?