The difference between Event and Phenomenon

When used as nouns, event means an occurrence, whereas phenomenon means a thing or being, event or process, perceptible through senses.

Event is also verb with the meaning: to occur, take place.

check bellow for the other definitions of Event and Phenomenon

Event as a noun:

An occurrence; something that happens.
Event as a noun:

A prearranged social activity (function, etc.)

Examples:

"I went to an event in San Francisco last week."

"Where will the event be held?"
Event as a noun:

One of several contests that combine to make up a competition.
Event as a noun:

An end result; an outcome (now chiefly in phrases).

Examples:

"In the event, he turned out to have what I needed anyway."
Event as a noun (physics):

A point in spacetime having three spatial coordinates and one temporal coordinate.
Event as a noun (computing):

A possible action that the user can perform that is monitored by an application or the operating system (event listener). When an event occurs an event handler is called which performs a specific task.
Event as a noun (probability theory):

A set of some of the possible outcomes; a subset of the sample space.

Examples:

"If <math>X</math> is a random variable representing the toss of a six-sided die, then its sample space could be denoted as {1,2,3,4,5,6}. Examples of events could be: <math>X = 1</math>, <math>X = 2</math>, <math> X \ge 5, X \not = 4,</math> and <math>X \isin \{1,3,5\}</math>."
Event as a noun (obsolete):

An affair in hand; business; enterprise.
Event as a noun (medicine):

An episode of severe health conditions.

Event as a verb (obsolete, intransitive):

To be emitted or breathed out; to evaporate.
Event as a verb (obsolete, transitive):

To expose to the air, ventilate.

Phenomenon as a noun:

A thing or being, event or process, perceptible through senses; or a fact or occurrence thereof.
Phenomenon as a noun:

(extension) A knowable thing or event (eg by inference, especially in science).
Phenomenon as a noun:

(metonymy) A kind or type of phenomenon (sense 1 or 2).
Phenomenon as a noun:

Appearance; a perceptible aspect of something that is mutable.
Phenomenon as a noun:

A fact or event considered very unusual, curious, or astonishing by those who witness it.
Phenomenon as a noun:

A wonderful or very remarkable person or thing.
Phenomenon as a noun (philosophy, chiefly, [[Kantian]], _, [[idealism]]):

An experienced object whose constitution reflects the order and conceptual structure imposed upon it by the human mind (especially by the powers of perception and understanding).