What does Load Testing primarily address?

Load testing primarily addresses the application's capability to function under anticipated user loads. This type of testing is crucial for understanding how an application behaves when multiple users access it simultaneously or when subjected to high traffic conditions. The goal of load testing is to ensure that the application can handle expected user interactions without degrading performance or crashing.

By simulating user demand, developers can identify bottlenecks and limitations in the system before it goes live, allowing them to make necessary adjustments to improve performance and scalability. This proactive approach helps to enhance the overall user experience and ensures that the infrastructure can support user expectations.

The other options, while important aspects of software development and testing, do not focus specifically on the concept of load testing. For instance, adaptability to new features pertains to regression and feature testing, user interface design testing focuses on usability rather than load, and historical performance reflects past metrics rather than current capacity and readiness for user load.