Difference between MapReduce of Couchbase and that of Hadoop?

Recently on a webinar by Couchbase, they said that Hadoop be used for processing large log files and Couchbase for presenting it to the application layer. They mentioned that the map reduce of Couchbase and Hadoop was different and suitable for the respective use case mentioned.

I was going to use Couchbase map reduce for processing large amouont of log file. Can some one please clarify the exact difference between the two map reduce? Are there any features in Hadoop which makes it more suitable for processing large log files? The application I am developing does not involve lot of users - its an internal application, but it would be required to store, analyse and present a huge amount of log file.