According to Google, millions of people search for hotels, and the search engine has decided to make it easier for travelers to find a hotel to stay in (and for Google to monetize these searches). To this end, there have been changes made to how hotel results show up:
We’ve been evolving the way hotels appear in search results on Google to include more structured, relevant and dynamic information — like rates, availability, locations, user reviews, editorial descriptions, Google Street View, and high resolution photos.
Results from partners (read: businesses paying Google money) will allow people to click on “Book” to make a reservation, which I assume simply takes the person in question to the hotel’s website. In the web version, people have the ability to choose a check-in and check-out date to confirm availability before booking. Additionally, regular AdWords ads appear above Hotel Ads, followed by standard SEO results.
It is also noted that via Google My Business, advertisers have the ability to upload photos and connect map results to their locations. Advertisers are also able to offer potential guests 360 degree views of their hotel via Google Maps Business View.