Our understanding of brain function depends on the measurement and analysis techniques at our disposal. To fully understand the value of a technique, we need to consider its capabilities and limitations and be aware of its place in the wider landscape of brain imaging. Electroencephalography (EEG) offers a way to observe brain activity in near real time and is widely applicable across many research and clinical applications. It can be quantitative, objective, has good test–retest reliability, and is a rich source of information. In this chapter, we consider how EEG developed as a research tool, its place within the landscape of brain imaging, and the future of EEG.