Description is used in all forms of writing to create a vivid impression of a person, place, object or event.
It may:
describe a special place and explain why it is special;
describe an important person in your life;
describe / create characters;
describe a personal experience;
engage a reader's attention;
give information (such as describing an animal within a report).
Structure
The first sentence introduces and classifies the topic.
Language
The description may show rather than tell the reader what something/ someone is like using precise similes or metaphors to create images/pictures in the mind. Strong development of the experience "puts the reader there" focusing on key details. It is focused and concentrates only on the aspects that add something to the main purpose of the description
If it is a technical/scientific description it will use technical/scientific language.
It relies on precisely chosen vocabulary with carefully chosen
adjectives,
adverbs and precise nouns
It uses action verbs (bites, squirts) or relational verbs (is/are).
Technical/scientific descriptions use the present tense.