Lazy loading means delaying the loading of any content until it becomes necessary. For example, on a long page, images that are currently not visible do not need to be uploaded. Only when the user scrolls the page on top or next to it, they are received from the server.
Endless scrolling refers to new content loaded when the end of the page is reached, so the effect of an infinitely long page is created (mainly to avoid tedious paging).
So yes, they are different, but connected.