View multiple webpages in one window. Click next to Tab Groups in the sidebar.
Organize with Tab Groups. When you’re doing research for a project or vacation, you can open several tabs, then save and organize them in groups. When the sidebar next to the Tab Group that you want to share, choose Share Tab Group, then click Messages. Once you’ve shared a Tab Group, collaborators can add their own tabs, and you can see what page others are currently viewing when in the Tab Group.
Note: Tab Groups are available across devices that are logged into iCloud with the same Apple ID, so you have access to your tabs from anywhere.
Learn more. See the Safari User Guide.