Differentiation is the act of getting the rate of change of a given function,
Todo: #incomplete
See finding derivatives.
The order of derivative is the number of time that the derivative of a function has been taken, for example if you took the derivative of
For example, given the function
The difference between explicit and implicit differentiation relies of the function that you are working with. If the function
If the function is written in terms of another variable then it is said to be in an implicit form. The function
For more complicated implicit equations it can be difficult to get it into an explicit form, you can instead use multivariable calculus to solve the equation (see chapter 14 - sections 5-6 below).
Source and further reading: Implicit Differentiation and Multivariable Calculus Notes - Chapter 14 - Sections 5-6