The document provides an introduction to radial compressors, also known as centrifugal compressors. It discusses the main components of a centrifugal compressor, including the inlet, impeller, diffuser, and collector. It explains how gas enters the impeller and is pushed outward, creating high pressure and compression. Applications include gas compression for natural gas pipelines and offshore platforms. Centrifugal compressors have advantages like wide operating ranges, high reliability, and efficiency. Their disadvantages include instability at low flows and sensitivity to gas composition changes.