The User Interface (UI) has changed from the original one you may be familiar with. This is due to the WordPress version 5.0 update to the editor. The new editor is much more visual, and is built using blocks to plug components into each page. All pages can be edited through the Classic Editor until you make the choice to edit the page in the Block Editor.
Present in the block editor are a few icons that are new to our users. Here you can find out more information on them.
Multi-dotted icon – This icon signifies that the selected element can be moved by drag and drop. This is specifically enabled for rearranging the order of blocks in your page and cards within the Cards block.