These are ``scientific terms"-they refer to concepts in mathematics. There are many ways of defining them, that depend on the level of abstraction desired.
I have a feeling that a century ago people were subjected to fear of death by the world wars. Most inventions are due to military funding. Somehow people were accustomed to deep thinking and conscious speech which currently people lack.
Differentiation is a term used in calculus to refer to the change in, which properties experiences concerning a unit change in another related property.
Integration is a term used in calculus to refer to the formula and the procedure of calculating the area under the curve.
Number systems own arithmetic that determines how numbers are distributed over space. A single line distributes all real numbers. Another single line or a three-dimensional space determines how spatial numbers are distributed by their arithmetic. Continuums obey the arithmetic of the underlying number system. Continuums can change. Differential calculus is the arithmetic of change.
Real number and spatial numbers mix into complex numbers and quaternions. Dynamic change of continuums can be described by complex differential calculus and by quaternionic differential calculus. In these situations, the real number part takes the role of progression.
Differentiation is used to study the small change of a quantity with respect to unit change of another. On the other hand, integration is used to add small and discrete data, which cannot be added singularly and representing in a single value.