What are brocas aphasia, and wernicke's aphasia?

Aphasias: Aphasia is a problem with language (with speech sounds being normal). Wernicke and broca's areas are regions of the brain where damage results in aphasia. Wernicke's aphasia, described as 'word salad', many words not making sense, while broca's aphasia is described as 'telegraphic', few words only. Aphasia can be 'expressive' for language output, or receptive. Google the names for brain maps.

Different: Broca's aphasia is difficulty in expressing speech. Werniche's aphasia is difficulty in understanding speech. That's oversimplified but still an adequate answer.