Hello Nutrivce and welcome to our helpful forum -
Yep, like said, the differential is leaking oil -
hat seems to be a relatively rare happening.
If you are a DIY kind of guy, you may consider cleaning up the area, then see if you can tell where the leak is coming from. If it's leaking from the drain plug, I would suggest you replace the drain plug washer (might as well change the oil while you are at it).
If the leak is coming from another part, you may try tightening the bolts that hold the rear cover on (use torque wrench).
If it still leaks, unless you are a big time DIY person, I'd suggest you drive it slowly to have a shop and have them fix it.
OR
Do it the humfrz way, make an appointment at a shop (don't drive it in the meantime, except to the shop) and ask them to fix it -
humfrz