What are the main components of the Selenium tool?

Selenium consists of several main components:

1. Selenium WebDriver — the primary tool for browser automation. It allows writing scripts that control the browser directly.

2. Selenium IDE — a browser plugin that enables recording and playback of tests without programming.

3. Selenium Grid — allows running tests in parallel on different machines and browsers, speeding up testing.

4. Selenium RC (Remote Control) — an outdated component that was previously used to control browsers via a server.

In modern projects, WebDriver and Grid are most commonly used for creating and scaling automated tests.