First let's look at derivatives. The derivative of a function will evaluate the rate of change for a point in the domain of that function. When we deal with a constant rate of change, such as the slope of a line in a linear equation, it is easy to figure out how that function is changing at any given point. When we are dealing with other sorts of functions, we need to look closer and identify the rate of change on specific intervals (such as how does it change between x=1 and x=2 or more specifical between x=1.1 and x=1.2).
Derivatives can be applied in many contexts, such as determining maximum profits in a business model, maximum area given various parameters, or used within the context of physics.
Integration works backwards from the derivative to find the original function that it was derived from.
There are much more specific details and a lot of different methods or formulas for finding both the derivative and the integral but I wanted to share with you how I understand it (having recently been reviewing calculus). An important part of calculus is it's exploration of change rather than static situations.