Yahoo! and Google are examples of:

Yahoo! and Google are examples of horizontal portals because they serve as gateways to a wide range of information and services across various topics and industries. Horizontal portals provide access to a variety of resources, including news, weather, search functionalities, email, and other online services, catering to a general audience rather than focusing on a specific niche.

This broad scope allows users to find and access diverse content and tools from a single platform, illustrating the concept of horizontal portals that aggregate content from multiple areas of interest. In contrast, vertical portals focus on a specific industry or topic, while social media platforms and e-commerce sites serve distinct functions related to social networking and online shopping, respectively.