It's important to realize that "bridge camera" is not a technical term. It's a marketing term *, made up to sell more-expensive cameras to intermediate photographers who are beyond point and shoots but are intimidated by the cost or complexity of a SLR.
Generally, the things sold as bridge cameras are bulky point and shoots which kind of look like they might be an SLR. Usually, they have superzoom lenses built-in. Somewhat ironically (or maybe just unfortunately), this isn't what someone needs if they really wants a "bridge" to go from naïve to knowledgeable photography.
There's a little more on this in the answers to this question Is there any bridge camera with an interchangeable lens? (To which the answer is: by definition, no.)
I think this term isreally should be obsolete in this decade, as the market has many great particularly obsoleteactual this year, with a new crop of crazy-cool intermediate cameras that are definitely not point-and-shoot in the sense of no control or advanced functionality. The new Canon G1 X, which has a large (basically micro-4/3rds sized) sensor but a non-interchangeable zoom lens is a poster-child for this, but also pretty much all the lower-range mirrorless interchangeable lens cameras too. Basically, there's a whole bunch of advanced cameras which are not DSLRs but definitely notalso beyond point and shoots eithershoot. One could apply the term "bridge" to all of these, but I don't think it's very useful.
I recommend ignoring this term and talking about specific cameras (or groups of cameras — all the small-sensor superzooms are basically identical) or specific features (like a large sensor in a compact camera body).
* See newspaper article from 1998 about the "new" type of camera.