What is the meaning of Differential?

Of or pertaining to a difference.

Dependent on, or making a difference; distinctive.

Having differences in speed or direction of motion.

Of or pertaining to differentiation or the differential calculus.

The differential gear in an automobile, etc.

A qualitative or quantitative difference between similar or comparable things.

One of two coils of conducting wire so related to one another or to a magnet or armature common to both, that one coil produces polar action contrary to that of the other.

A form of conductor used for dividing and distributing the current to a series of electric lamps so as to maintain equal action in all.

A quantity representing an infinitesimal change in a variable, now only used as a heuristic aid except in nonstandard analysis but considered rigorous until the 20th century; a fluxion in Newtonian calculus, now usually written in Leibniz's notation as ${\displaystyle \mathrm{d}x}$.

A function giving the change in the linear approximation of ${\displaystyle f}$ at a point ${\displaystyle x}$ over a small interval ${\displaystyle \Delta x}$ or ${\displaystyle \mathrm{d}x}$, the function being called the differential of ${\displaystyle f}$ and denoted ${\displaystyle \mathrm{d}f(x,\Delta x)}$, ${\displaystyle \mathrm{d}f(x)}$, or simply ${\displaystyle \mathrm{d}f}$.

Any of several generalizations of this concept to functions of several variables or to higher orders: the partial differential, total differential, Gateaux differential, etc.

The Jacobian matrix of a function of several variables.

The pushforward or total derivative of ${\displaystyle \varphi }$: a linear map from the tangent space at a point ${\displaystyle x}$ in ${\displaystyle \varphi }$'s domain to the tangent space at ${\displaystyle \varphi (x)}$ which is, in a technical sense, the best linear approximation of ${\displaystyle \varphi }$ at ${\displaystyle x}$; denoted ${\displaystyle \mathrm{d}{\varphi }_x}$.

Any of several generalizations of the concept(s) above: e.g. the Kähler differential in the setting of schemes, the quadratic differential in the theory of Riemann surfaces, etc.

a differential gear

an infinitesimal change

the differential operator

Source: wiktionary.org