A camera, by the most basic of definitions, captures still photographs or video, either on film or digitally. The importance of the camera is not in the device itself, but in what it produces. Photographs and video have become vital to communication, education and preservation of history.
Cliches are cliches because everyone has heard them before. A picture is worth a thousand words. Photos and videos taken with cameras are used to communicate, to tell stories. The camera was and is a tool or war, used to capture events or people. It is also a tool of everyday lives--just browse an album on Facebook and you'll have "read" a kind of story.
Some people learn by hearing, others by writing, some by seeing. The camera has added a new dimension to education, allowing photographs and video to become learning tools. Imagine a medical school textbook without photographs. Learning takes on a whole new dimension when a student can visualize the medium.
The camera helps to create and preserve memories of historical and/or sentimental value. Famous photographs of notable moments and events from history were made possible by the camera. Every day babies are born, people get married, and all of it is documented with cameras, a source of helping us remember our past. The camera is a valuable source to preserve history.