Pre-Algebra introduces a student to variables, expressions, equations and more. The student also learns important concepts like Factors and Multiples, Ratios and Proportions, Exponents which are immensely useful in Algebra-I and Algebra-II
Algebra-I introduces the student to areas which have real world applications. Functions, Quadratics and Polynomials are such topics which are used in everyday technology building. Proper understanding of Pre-Algebra concepts like Factors, Multiples, Variables, Expressions and Equations is a pre-requisite.
Algebra-II is an extension of Algebra-I introducing more complexity in some topics like Polynomials, Complex Numbers and Exponents. You will also learn newer and more complex topics in trigonometry which build a bridge to Pre-Calculus topics.