> ## Documentation Index > Fetch the complete documentation index at: https://docs.vals.ai/llms.txt > Use this file to discover all available pages before exploring further. # Introduction The Vals platform is designed to allow you to easily test LLM applications -- copilots, RAG systems, and more. This documentation covers how to use both the web application and the CLI/SDK tools. Vals Platform Concept At the core of the platform are **Test Suites**. Each Test Suite is designed to evaluate your model’s performance in a specific area. A Test Suite is composed of multiple **Tests**. Each "Test" has exactly one input, typically representing user input. For example, if you are testing a math copilot, an input might be: > What is 3 \* 2? Each Test also includes a set of **Checks**. A Check evaluates whether the model's response meets a specific expectation. For the input above, a Check might be: > The output includes the number 6. The rest of this documentation explains how to create Test Suites and run them against models. To get started, see [Creating Test Suites](/web_app/creating_test_suites).