Apparently it’s a European concept for a hotel that caters to the whole family. They often offer meal plans you can add to your booking. Full spas are often on site. They can feature all types of activities on site, such as swimming, volleyball, skiing, horse back riding, you name it. Each kinder hotel is different and has unique features. The biggest highlight for families is the on site kids program featuring daycare!!! There’s an age minimum at some kinderhotels but I always picked a kinder hotel that had daycare for my young toddlers. kinder hotels allow you to drop your kid off for a specific period of time throughout the day. Some split it up knowing that young kids nap in the afternoon. I’ve been to one that let me drop my 3yo off pretty much all day and they fed her while there!. During that time the hubby and I were free go enjoy all the activities on site kid free!! I’ve looked for hotels with this concept in America and it’s much less common. I see that Club Med has some facilities with a similar concept but their age minimum for daycare is much older. In Europe, especially in Austria and Germany it is so easy to find. I can post the links for kinderhotel search portals anyone is interested!
Hello @StephaniS
yes, this is a quite popular concept in Europe. While it name is Kinder Hotel or Kids Hotel, but in fact it is more to ensure that the parents can relax 
As a father of 3 kids I need to say, that the concept is in fact interesting, while I never would do so, as I cannot sit in a hotel. I need to discover new places and the hotel my family only need for sleep.
As well, at least in Europe, most of this hotels are quite expensive.
But, yes, it is an option and as I understand they are developing very well in some key touristic centers.
Here in Germany Kinder hotels are very common. I enjoyed them a lot with my family during the past few years.
They’re so perfect for families!
I agree that they can be pricey, but if you consider it a staycation your stay can sometimes be equivalent to traditional vacation spending with lots of eating out , activities, and exploring. The portals always helped me find one within my budget