In times gone by some of the finest mathematicians either came from Greece and the Mediterranean states or they had some knowledge of Greek alphabets. So it was natural for them to turn to Greek alphabets to name the new symbols that they were developing. That is why when modern day math students open their textbooks they find the chapters filled with words like Alpha, Beta, Delta and Gamma.
Early on in their academic life math students learn that Delta stands for change in mathematics. In formulas they use the variable “x” to represent an object, and then they use the symbol “Δ” along with the “x” to denote a change in the value of the variable. Students of physics and engineering find that they use Delta extensively in their formulas.
Students of algebra learn that Delta in their discipline represents the discriminant of a polynomial equation. They use Delta when they are working with quadratic equations. Students of geometry use the lower case delta to represent the angles in their geometric shapes. When working with partial derivatives equations they use the lower case delta symbol to represent partial derivatives.
When students start to learn advanced mathematics, they get introduced to a concept known as Kronecker Delta. This represents a relationship between two integral variables. The answer is one if the two variables are equal. If the two variables are not equal then the answer is zero.
Basic math students might not have to spend so much time thinking about Delta, but once they go into high level geometry, physics, chemistry and engineering then they will have to master the art of understanding Delta.