Adobe serves an enormous part of the image-editing market, whether photographers like it or not. They are an industry leader in graphic design, photo editing and photo management software---the standard in the industry for many people.
Lightroom, the photo processing software, has professional-grade editing and organizing tools, but still maintains its usability. The Creative Cloud of Lightroom version is part of Adobe’s annual subscription-based Photography Plan, which includes Photoshop CC, so you’re getting two photo-editing applications designed to work alongside each other.
Adobe's recent upgrade to Lightroom has seen the emergence of two Lightrooms--Lightroom Classic CC (an updated version of the desktop Lightroom that we know--its Lightroom 7) and Lightroom CC (an entirely redesigned app designed to work alongside Adobe’s equally new cloud-based storage system)--a cut down version (Lightroom Mobile?), that is a shift to a more mobile-first workflow which allows you to manage your photos wherever you are and whatever the device.
The current subscription model for Lightroom CC means that we rent Adobe’s apps rather than buying a licence--permanently renting the tools we use to create. The shift is from software to rental ware. I have been using the stand alone Lightroom 5 (desktop) up to now, but I recently purchased Lightroom 6 (desktop) as part of my film order from B+H. I realize that I am essentially getting a two-year-old version, feature wise, as compared to the subscription version. I appreciate that the differences between the subscription version Lightroom Classic and and the standalone version of Lightroom 6 are becoming significant, but I don't really need all the updates or the extraneous options.