English Language Learners Stack Exchange is a question and answer site for speakers of other languages learning English. It only takes a minute to sign up.
Sign up to join this community
It seems that it is correct usage to talk about the topology of the brain, but not the topography of the brain. And it seems like correct usage to talk about the topography of human organs, but not the topology of human organs.
Then what is the precise difference between topology and topography?
topology
(1) is a branch of mathematics that studies of how properties of points and sets become connected spaces and how the properties of these spaces change or do not change under continuous transformations
(2) is more generally the way in which the fundamental constituents or components of a physical or abstract space interrelate and are arranged to form the whole.
topography
(1) is the mapping or description of the physical features of a geographic area and especially the location and height of natural and artificial land features
(2) is more generally any mapping or description of the locations of features on a surface on, or within an entire composite object.
So:
When we speak about the topology of the brain, we are concerned with how the fundamental components of the brain (neurons) interrelate and are arranged to form the whole brain.
When we speak about the topography of human organs (with careful respect to a certain anatomical surface, for example the thoracic cavity), we are talking about describing with a visual or verbal description of the location of features (organs) on that anatomical surface, inside of the body.
I am not going to give you a definition of these terms because you can easily look them up in a dictionary, and the other answer given already explains these words.
However, here's a tip if you ever find yourself without access to a dictionary, and you find a word you don't understand. A good starting point to help you guess the meanings of words in English of Latin/Greek origin, or at least get a rough idea of their meaning, is to learn the meanings of common suffixes.
-logy = branch of learning/study
-graphy = something written or otherwise represented, such as by drawing or imaging, etc.
Incidentally, the root word "topo" here comes from Greek τόπος (topos), which means place/location.
There are many words that use these suffixes. To name but a few: geology, geography, theology, calligraphy, morphology, stratigraphy, meteorology, photography, biology, biography, criminology, radiology, radiography, etc.
There's a good resource here on Wiktionary for a list of common suffixes used in English.
