What is multithreading in programming?

Multithreading in programming refers to a model that enables multiple threads to run concurrently within a single program. Each thread represents a separate flow of control, allowing tasks to be executed in parallel or interleaved. This capability is particularly beneficial for optimizing the use of CPU resources, as it allows a program to perform multiple operations simultaneously rather than sequentially.

For instance, in applications that need to handle multiple user inputs or perform various tasks (like downloading data while processing user interface interactions), multithreading allows these operations to occur without waiting for one to finish before starting another. This not only enhances performance but also improves responsiveness in applications, as users can interact with the program while background tasks are being executed.

The other options do not accurately describe multithreading. Linear execution refers to a single-threaded model where code is executed in sequence. Techniques for debugging and testing software performance focus on identifying and resolving issues or measuring efficiency, rather than enabling concurrent task execution. Understanding multithreading is crucial for developing efficient, responsive applications, especially in environments that demand high performance and speed.