The Denon AVR-2105 is a home theater receiver that was first released in 2005. It features a power output of 90 watts per channel, support for Dolby Digital and DTS audio formats, and various connectivity options including HDMI, component, and composite inputs. The AVR-2105 also includes multi-zone functionality, allowing for audio playback in different rooms. It is a mid-range receiver that offers a good balance of features and performance.