buyer's and seller's markets?

in my earliest real estate readings i encountered the market cycles, shown in graphical form, resembling a normal up/down wave.

on one side would be a buyer’s market (buyers I and buyers II), and then sellers I and sellers II.

this seemed to be such a normally accepted thing in the book i was reading it in, yet in my real estate principles textbook, there’s about a page devoted to cycles, no graphs, and no mention of a buyers market, or of a sellers market

how commonly accepted are these terms, buyers and sellers markets? how clearly defined are they? how well does what i described follow real life? (i hope this makes sense, will clarify if it came out wrong)

As with most things you read in a text book, the picture presented looks black and white by definition, graph or representation. In practice, however, it’s gray. The terms buyer’s and seller’s markets are widely used, but not very well defined. Many people will have different ideas of whether similar markets are the same. For good exercise on this, go to realtytimes.com and pick a market, then look at how the realtors rate the same market. For the most part there is a wide disparity between opinions. This means that the terms, while often thrown about, have little concrete meaning and are often viewed diffferently.