Algebra is a branch of mathematics which deals with arithmetic calculations using symbols to signify unknown numbers and to find the relation between mathematical objects. Classical algebra focuses on execution of arithmetic calculations involving letters or symbols to represent specific numbers without using precise values. Operations of quadratic equations, polynomials, simultaneous equations, factorization, etc. come under classical algebra. Branches like trigonometry and logarithms are also categorized in classical algebra. Modern or abstract algebra describes the behaviour of mathematical objects. Groups, rings, fields, vector spaces are all branches of abstract algebra.