What is the Difference Between Runnable and Thread?

The main difference between Runnable and Thread in Java lies in their design, inheritance, and resource sharing capabilities. Here are the key differences between the two:

1. Extending vs. Implementing: A class extending Thread cannot extend any other class due to Java's single inheritance constraint. On the other hand, a class implementing Runnable can implement multiple interfaces, providing more flexibility and better object-oriented design.
2. Memory Consumption: Thread consumes more memory because each thread creates a unique object and gets associated with it. In contrast, Runnable requires less memory, as multiple threads share the same object.
3. Limitation: A class cannot extend another class if it extends the Thread class. However, if a class implements the Runnable interface, it can extend another class.

In summary, implementing Runnable is generally preferred over extending Thread due to its better object-oriented design, reusability, and resource sharing capabilities. It also allows for easier extensibility and flexibility in creating and managing threads.

Comparative Table: Runnable vs Thread

Here is a table comparing the differences between Runnable and Thread:

Implementing Runnable is generally preferred over extending Thread because it allows for more flexibility, better inheritance, and cleaner separation between code and implementation.