Can you teach me calculus in a more simplest form to understand even what letters stands for

Calculus is a branch of mathematics that studies change and accumulation. It helps us understand how things change over time or space, and how to find the total amount of something when its rate of change is known. There are two main parts: 1. Differential Calculus: This deals with rates of change and the slope of a curve at any point. It answers questions like: How fast is something moving at an exact moment? How quickly is a quantity increasing or decreasing? The main concept is the derivative*. Common notation: dy/dx or f'(x). y and x are variables, where y often depends on x. For example, y could be distance and x* could be time. f(x) represents a function, which is a rule that tells you how to get y from x*. d in dy/dx stands for "differential" or "a very small change." So, dy/dx means "the rate of change of y with respect to x*." 2. Integral Calculus: This deals with accumulation and the area under a curve. It answers questions like: What is the total distance traveled if I know my speed at every moment? What is the total volume of an irregularly shaped object? The main concept is the integral*. Common notation: ∫ f(x) dx. ∫* is the integral symbol, which looks like a stretched "S" and stands for "sum." It means we are summing up infinitely many tiny pieces. f(x)* is the function we are integrating (the rate of change). dx indicates that we are summing these pieces with respect to the variable x*. In simple terms, differential calculus helps you find the rate from the total, and integral calculus helps you find the total from the rate.