I believe the answer is pointed arches, correct me if I'm wrong. Romanesque architecture has thick stone walls, small windows, and rounded arches. I do not believe they have any pointed arches. As you can see in the photo attached there are all of the above, except pointed arches.
It is called Romanesque style in architecture to the result of the reasoned and harmonic combination of constructive and ornamental elements of Latin, oriental (Byzantine, Syrian, Persian and Islamic) and northern (Celtic, Germanic, Norman) origins that formed in Christian Europe during the first centuries of the Late Middle Ages. The main buildings of the architecture were: churches, monasteries, abbeys and cathedrals.
