WordPress now ships with Block Editor (a.k.a Gutenberg) as the default WordPress editor. It takes a new block-based approach to create content where everything on your page is considered a block (headings, paragraphs, images, etc).
You can easily add, remove, and change the order of the blocks. This is more interactive than the previous TinyMCE-based editor and makes things easy for casual WordPress users.
Go through the following official articles to explore more about WordPress Editor.