Main Difference
The main difference between Parameter and Perimeter is that the Parameter is a measurable characteristic and Perimeter is a path that surrounds an area.

Parameter
A parameter (from the Ancient Greek παρά, para: “beside”, “subsidiary”; and μέτρον, metron: “measure”), generally, is any characteristic that can help in defining or classifying a particular system (meaning an event, project, object, situation, etc.). That is, a parameter is an element of a system that is useful, or critical, when identifying the system, or when evaluating its performance, status, condition, etc.
Parameter has more specific meanings within various disciplines, including mathematics, computing and computer programming, engineering, statistics, logic and linguistics. Within and across these fields, careful distinction must be maintained of the different usages of the term parameter and of other terms often associated with it, such as argument, property, axiom, variable, function, attribute, etc.

Perimeter
A perimeter is a path that surrounds a twodimensional shape. The term may be used either for the path or its length—it can be thought of as the length of the outline of a shape. The perimeter of a circle or ellipse is called its circumference.
Calculating the perimeter has several practical applications. A calculated perimeter is the length of fence required to surround a yard or garden. The perimeter of a wheel (its circumference) describes how far it will roll in one revolution. Similarly, the amount of string wound around a spool is related to the spool’s perimeter.

Parameter (noun)
A value kept constant during an experiment, equation, calculation or similar, but varied over other versions of the experiment, equation, calculation, etc.

Parameter (noun)
a variable that describes some system (material, object, event etc.) or some aspect thereof

Parameter (noun)
An input variable of a procedure definition, that gets an actual value (argument) at execution time (formal parameter).
“Roughly, a tuple of arguments could be thought of as a vector, whereas a tuple of parameters could be thought of as a covector (i.e., linear functional). When a function is called, a parameter tuple becomes “bound” to an argument tuple, allowing the function instance itself to be computed to yield a return value. This would be roughly analogous to applying a covector to a vector (by taking their dot product (or, rather, matrixproduct of row vector and column vector)) to obtain a scalar.”

Parameter (noun)
An actual value given to such a formal parameter (argument or actual parameter).

Parameter (noun)
A characteristic or feature that distinguishes something from others.

Parameter (noun)
In the ellipse and hyperbola, a third proportional to any diameter and its conjugate, or in the parabola, to any abscissa and the corresponding ordinate.
“The parameter of the principal axis of a conic section is called the latus rectum.”

Parameter (noun)
The axes which determines the position of any plane.

Parameter (noun)
The fundamental axial ratio for a given species.

Perimeter (noun)
The sum of the distance of all the lengths of the sides of an object.

Perimeter (noun)
The length of such a boundary.

Perimeter (noun)
The outer limits of an area. circumference

Perimeter (noun)
A fortified strip or boundary usually protecting a military position.

Perimeter (noun)
An instrument for determining the extent and shape of the field of vision.

Parameter (noun)
a numerical or other measurable factor forming one of a set that defines a system or sets the conditions of its operation
“there are three parameters by which a speaker is able to modify the meaning of the utterance—pitch, volume, and tempo”

Parameter (noun)
a quantity whose value is selected for the particular circumstances and in relation to which other variable quantities may be expressed.

Parameter (noun)
a numerical characteristic of a population, as distinct from a statistic of a sample.

Parameter (noun)
a limit or boundary which defines the scope of a particular process or activity
“the parameters within which the media work”

Perimeter (noun)
the continuous line forming the boundary of a closed geometrical figure
“the perimeter of a rectangle”

Perimeter (noun)
the outermost parts or boundary of an area or object
“a perimeter fence”
“the perimeter of the garden”

Perimeter (noun)
an area away from the basket, beyond the reach of the defensive team
“he was very patient in working the ball around the perimeter”

Perimeter (noun)
an instrument for measuring the extent and characteristics of a person’s field of vision.