1. Customization and Design: Google Sites is more limited in terms of design and customization options compared to Squarespace. Squarespace offers a wide range of professionally designed templates that are highly customizable, allowing users to create unique and visually appealing websites easily. Google Sites, on the other hand, has more basic design capabilities with fewer template choices, restricting the overall creativity and flexibility of the website.

2. E-commerce Functionality: Squarespace has robust e-commerce features that allow users to set up online stores, manage inventory, process payments, and track orders efficiently. Google Sites, on the other hand, lacks advanced e-commerce capabilities, making it more suitable for simple informational websites rather than online businesses looking to sell products or services directly.

3. SEO (Search Engine Optimization): Squarespace provides more advanced SEO tools and features compared to Google Sites. Squarespace allows users to optimize their websites for search engines by customizing meta tags, URLs, and image tags, thereby improving online visibility and rankings. Google Sites has limited SEO functionality, making it harder for users to optimize their websites for search engine rankings.

4. Scalability and Growth: Squarespace is well-known for its scalability and ability to grow with the user's needs. Users can easily upgrade their plans to access more features and resources as their websites expand. On the other hand, Google Sites may not be as scalable for larger projects or businesses, as it is more suitable for basic websites or small-scale projects with limited growth potential.

5. Third-party Integrations: Squarespace offers a wide range of third-party integrations and plugins that users can easily add to their websites to enhance functionality and features. This includes integrations with popular tools for marketing, analytics, and e-commerce. Google Sites, however, has fewer third-party integrations available, which may limit the overall functionality and capabilities of the website.

6. Support and Customer Service: Squarespace provides dedicated customer support through various channels such as live chat, email, and extensive online documentation. Users can quickly get help and assistance for any issues or questions they may have. In contrast, Google Sites may have limited support options, making it more challenging for users to troubleshoot problems or get timely assistance when needed.

In Summary, Squarespace offers more advanced design, e-commerce, SEO capabilities, scalability, third-party integrations, and customer support compared to Google Sites, making it a preferred choice for users looking to create professional and feature-rich websites.