It's a big question for many, as to which Photo Editing Software is better- Adobe Photoshop or Adobe Lightroom.
I would try to answer this question by telling you the differences between this two software, helping you to chose the one better for your work.
Photoshop is a photo editing software created by Adobe. It's a beast, that can be used by photographers, graphic designers, architects, publishers, etc. It is a pixel level editor.
Lightroom is also a photo editing software, having a set of Photoshop features designed only for Photographers. It covers the majority of all the image editing tools you will most likely need. It helps you to manage all your photos in a neat manner. It has an autosave feature which means that you don't have to worry about saving your edit everytime you exit Lightroom.
When to use Lightroom?
If you are editing a RAW photo then you should first import it to Lightroom so that you don't need Adobe Camera Raw like in Photoshop and your images will be organized as well. If you are a beginner in photography you will be satisfied with all the features of Lightroom and it is also much easier than photoshop.
Consider adding Photoshop to your workforce after you are familiar with the things Lightroom is not capable of Doing.