Newbie - Site Advice Please

I have just bought my very first Motorhome and have never visited any campsites other than static home sites. I have noticed that when using the advanced search to find sites, there is an entry for "Suitable for Motorhomes" in the search criteria. Could someone please advise on the following points.

1. What makes a site "suitable" for motorhomes?

2. Is there any specific equipment I need for my vehicle to make it suitable for non suitable sites?

Thanks in advance for any advice offered.

Martin.