Application servers and dedicated servers are two different concepts, and they refer to different server types and uses respectively. Here are the main differences between them:

　　application server:

　　Definition: An application server is a server specifically designed to host and run applications. It provides a runtime environment specific to where the application runs and handles the application's business logic, data access, and other related functions.

　　Features:

　　1. The application server usually runs on the operating system and provides the services and environment required for application running.

　　2. They handle transactions related to business logic, such as database access, transaction management, connection pool management, etc.

　　3. The application server supports multiple protocols and services, such as HTTP, HTTPS, SOAP, REST, etc., to communicate with clients.

　　4. Common application servers include Tomcat, Apache HTTP Server, Microsoft IIS, etc.

　　​dedicated server:

　　Definition: A dedicated server refers to an actual hardware server, usually an independent physical device with its own processor, memory, hard disk and other hardware components.

　　Features:

　　1. A dedicated server is a physical hardware device, usually placed in a data center or server room.

　　2. They can run one or more operating system instances and support hosting various types of applications.

　　3. The performance and resources of dedicated servers are limited, so they may be limited in handling large workloads or scenarios that require flexibility.

　　4. The emergence of virtualization technology makes it possible to run multiple virtual server instances on one dedicated server, improving resource utilization.

　　Summary of differences:

　　1. Different levels: The application server is a software-level service dedicated to running applications; while the dedicated server is a hardware device, which is the actual hardware that provides computing resources and operating environment.

　　2. Level of abstraction: The application server focuses more on the runtime environment and business logic of the application; while the dedicated server focuses more on the management and provision of hardware resources.

　　3. Versatility: A dedicated server can host multiple applications, while an application server is usually focused on supporting one or a set of specific types of applications.

　　4. Resource limitations: The resources of dedicated servers are limited, while application servers usually run on dedicated servers and can be dynamically expanded or contracted as needed.