OpenTable and SevenRooms are both technology companies that provide reservation and guest management systems for the hospitality industry. However, there are some key differences between the two:

1. Focus: OpenTable primarily focuses on providing online restaurant reservations, while SevenRooms offers a suite of tools for a wider range of hospitality businesses, including hotels, resorts, and event spaces.

2. Features: OpenTable provides a comprehensive reservation management system that integrates with a restaurant's point-of-sale system, allowing them to manage their reservations, guest data, and seating charts. SevenRooms offers a similar solution, but also provides additional tools for marketing and loyalty, as well as a robust guest data management system.

3. Pricing: OpenTable charges a per-cover fee for reservations made through its platform, while SevenRooms charges a monthly subscription fee.

4. User interface: OpenTable is known for its user-friendly and straightforward interface, making it easy for diners to search for and make reservations at restaurants. SevenRooms has a more complex interface, but provides a more comprehensive set of tools for managing guest data and marketing.

Ultimately, the choice between OpenTable and SevenRooms will depend on the specific needs of your business. If you're looking for a simple and straightforward solution for managing restaurant reservations, OpenTable may be the best option. However, if you're looking for a more comprehensive solution for managing your hospitality business, SevenRooms may be a better choice.