Chapter 1: ACS Overview 1.1 Instrument Design and Capabilities 1.1.1 Detectors 1.1.2 ACS Optical Design 1.1.3 ACS Geometric Distortion 1.1.4 ACS Performance after Servicing Mission 4 1.2 Basic Instrument Operations 1.2.1 Target Acquisitions 1.2.2 Typical ACS Observing Strategies 1.2.3 Data Storage and Transfer 1.2.4 Parallel Operations