WebDriver Vs RC

Architecture

RC required a separate server process relaying commands to the browser via injected JavaScript; WebDriver communicates directly with the browser through its native driver, with no intermediary server needed.

Speed and Stability

WebDriver is generally faster and more reliable since it avoids the extra communication layer RC depended on.

API Design

WebDriver's API is object-oriented and more intuitive, whereas RC's API used string-based Selenese commands routed through a server.

Current Status

WebDriver is the modern standard; RC has been deprecated and is no longer actively used in new automation projects.