Active matter, matter with self-propelling constituents, has recently sparked the interest of the soft matter scientific community. Active components may be biological i.e. bacteria, or even chemically driven particles. The ability of active matter to provide energy through motion at a microscopic level, produces interesting phenomena, such as effective interactions, swarming, internally generated flows and activity induced phase transitions. Here, we examine various aspects of model active matter systems, ranging from hydrodynamically induced synchronization, active transport effects and complex interactions between active and non-active components.