Respite care?

I am new to this site but have seen many posts about "respite care" for a week or so, as well as, nursing facility for up to a month...What is this all about? I have taken care of my Mom for 16 months 24/7, months before that from morning to night, and her errands, doctors etc for about 14 years. Seems that I can't even get home health to do anything. It has become very tiresome since I also have 3 kids (2 under 13) and hubby to care for. One sibling who won't even visit, the other one passed away. I have found the questions and advice on here so helpful and uplifting. Thanks for being there when I need to know that I am not alone. :)