Lightroom is definitely the program for catologing and keeping track of photos as well as post them to various services. It also has a "Camera Raw" much like photoshop. I use it ALL the time!
Photoshop CC 2014's plug-in - Camera Raw - and LR's Develop module are the same software - Adobe Camera Raw.
There are some very some minor differences between Camera Raw and LR's Develop module.
Photoshop CC 2014's other plug-in - Bridge - is a image browser application that can also be used to automate some of Photoshop CC's features.
Note that Adobe's $9.99 per month Photography Program subscription includes both Photoshop CC 2014 and Lightroom 5.6.
Lightroom is intended as a front end process for Photoshop CC, which is why both are included in the Photography Program.
Lightroom was designed for photographers that:
1. Routinely make
a lot of photos.
2. Make money from their photos.
To those ends, LR's primary reason for being is image database management.
Personal computers include an image browser application, so most people are familiar with using an image browser application.
Far fewer people know how to set up and use an image database application.
I see a lot of people who do not use LR's primary feature - image database management - effectively.
Photoshop Elements has a de-featured, consumer grade version of Camera Raw that has about 1/2 of ACR's (Camera Raw/LR Develop module) normal compliment of tools, features, and capabilities