The difference between paragraphs and line breaks:
Here is the first paragraph
And this is a 2nd paragraph
Here is a line of text in the 3rd paragraph
Here is a 2nd line of text in the same paragraph, but separated by a line break.
Press the Shift and Enter (Return) key together to make a line break.
Press the Enter key by itself to make a new paragraph.
This section is only relevant if you are still using the Classic Editor.
Understanding the Classic Editor
To save you from having to type paragraph tags in your posts and pages, WordPress automatically converts line breaks into paragraphs and new lines into line breaks.
In the Visual editor
Hitting the Enter (Return) key will end the paragraph you are writing and start a new one. If you want to start a new line without creating a new paragraph, press the Shift and Enter keys together.
In the Text editor
Leaving an empty line between 2 lines will automatically convert them into separate paragraphs, while continuing on the next line will convert it into a line break. Typing the following..
Here is a paragraph of text. Here is the 2nd paragraph, separated by an empty line. This is a new paragraph with a line break
..will result in the following HTML output:
<p>Here is a paragraph of text.</p> <p>Here is the 2nd paragraph, separated by an empty line.</p> <p>This is a new paragraph<br/> with a line break</p>
