The Heliospheric Imagers (HI), onboard the Solar and Terrestrial Relations Observatory (STEREO) spacecraft, observes quasi-continuously the variations in the electron density of the solar wind. These observations are providing us with new information about the so-called 'background solar wind' during solar minimum conditions. In particular, the evolution of the streamer belt (as well as the dynamics of helmet streamers) and Corotating Interaction Regions (CIRs) can be studied in detail using HI. These observations will be compared to magnetohydrodynamic predictions of the solar wind. The second part of the talk will focus on observations of Coronal Mass Ejections which are part of the so-called 'active heliosphere'. We will show how the direction and speed of propagation of CMEs can be inferred and how HI can be used for space weather predictions. The first comparison of CMEs as seen in HI with in-situ observations will be presented using spacecraft orbiting the planets of the inner heliosphere.