Use Topics to Organize Your Content in Chatter

You most definitely asked, and we most definitely answered by introducing topics in Lightning Experience. No need to set up anything, as our Lightning Experience org is automatically updated to support topics. View a topic detail page, edit the topic description, see how many people are discussing the topic, see trending and related topics, follow topics that interest you...in short, enjoy organizing the heck out of your Chatter feed. Topics even show up in global search results. So go on...tag away! This feature is new in Lightning Experience.

A post can have up to 10 topics, including topics added in comments. Assigned topics are associated permanently to the post in the system, even if you remove them visibly by editing the post. You can use topics on a record’s feed, but topics on objects aren’t available in Lightning Experience.

Topics in Lightning Experience