DSpace is an open source repository system that can store and distribute digital content over the web in various formats like text, video, audio, and data. It indexes content to make it searchable and preserves it long-term. The document provides step-by-step instructions for installing DSpace, including downloading required software like Java, Apache Maven, Apache Ant, PostgreSQL, Apache Tomcat, and DSpace source files. It describes configuring environment variables and databases, compiling the DSpace source code, and copying files to Tomcat to launch the DSpace repository.