Descriptive language - a literary technique which involves the detailed representation of a person, object, or place to signify its importance.
We do not have the time (or words) to use descriptive language in all of our writing—such a story would never get anywhere.
This is because descriptive language takes its time to bring a very important moment within a story to life. It's a bit like slow motion in a film, where the lower frame rate allows the viewer to better appreciate exactly what is happening in a key moment.
Let's consider an example of descriptive language from Chinua Achebe's 1958 novel Things Fall Apart, in which protagonist Okonkwo wrestles another man, Amalinze, known as the Cat:
The drums beat and the flutes sang and the spectators held their breath. Amalinze was a wily craftsman, but Okonkwo was as slippery as a fish in water. Every nerve and every muscle stood out on their arms, on their backs and their thighs, and one almost heard them stretching to breaking point. In the end Okonkwo threw the Cat.
Note how Achebe carefully sets the scene by using imagery to describe the sounds of the arena with its beating drums and singing flutes. He then describes the characters by using specific vocabulary (Amalinze was a wily craftsman) and a simile (Okonkwo was as slippery as a fish). Following this, Achebe takes time to narrate exactly what is happening to the wrestlers' bodies during the match, describing the effects of the contest on the various nerves and muscles in their bodies.
This careful, descriptive language draws the reader into the moment, helping them feel as though they are watching the match with the other spectators in the audience.
Again, writers do not have the time or words to use this style of writing throughout all of their stories.
However, during key moments which develop characters and advance the plot, descriptive language is an effective way to engage the audience and help them feel part of the story.