Above: The Dual NDVI Ultra Probe Unit is powered by a Nano Logger (enhanced by an array of beryllium spheres) and is ready for field action. The TSL2561 is a common luminosity sensor. It measures how bright it is and reports in units that relate to the brightness that people perceive (lux).
An adjective describes (tells us more about) a noun or a pronoun. For example: student is a noun. But we can say more about the student in our sentence by using an adjective: intelligent student; clever student; lazy student; good student... etc. So, here is a sentence: The teacher says Marie is a good student.
An adjective is a word used to modify or describe a noun or a pronoun. It usually answers the question of which one, what kind, or how many. (Articles [a, an, the] are usually classified as adjectives.) The young girl brought me a very long letter from the teacher, and then she quickly disappeared.