They are both carbon filters, but they are not the same.

I got concerned about water quality (specifically lead) right before the Flint after doing some plumbing work in my apartment. After some digging I found a report detailing PPM before and after filtration. Brita's generally filtered less than 20 percent of containment with the exception of things like chlorine which naturally off gas. The faucet systems generally removed 80-90%.

They're granulated. The good under sink filters are carbon block.