forms javascript jquery

What is the meaning of onsubmit=”return false”? (JavaScript, jQuery)

I know that the onsubmit event occurs when a form is submitted.

Generally, we are calling a method on the onsubmit event, like <form action="" onsubmit="myfunction()">.

Today I saw this, "<form action="" onsubmit="return false">". How does it work? I could not understand what is the meaning of onsubmit="return false".

PS: I found this when learning Ajax. It was a tutorial which explains how to submit data to a database without refreshing the page.