The difference between Anonymous and Unknown

When used as adjectives, anonymous means lacking a name, whereas unknown means not known.

Unknown is also noun with the meaning: a variable (usually x, y or z) whose value is to be found.

check bellow for the other definitions of Anonymous and Unknown

Anonymous as an adjective (not comparable):

Lacking a name; not named, for example an animal not assigned to any species.
Anonymous as an adjective (not comparable):

Without any name acknowledged of a person responsible

Examples:

"an anonymous pamphlet; an anonymous subscription."

"'anonymous author"
Anonymous as an adjective (not comparable):

Of unknown name; whose name is withheld

Examples:

"an anonymous author; an anonymous benefactor."

"The anonymous contributors of Wikipedia"

"No customer personal data will be retained unless it is rendered anonymous''."
Anonymous as an adjective (comparable, figurative):

Lacking individuality.

Examples:

"an anonymous office block in a soulless industrial estate"

Unknown as an adjective (sometimes, _, postpositive):

Not known; unidentified; not well known.

Unknown as a noun (algebra):

A variable (usually x, y or z) whose value is to be found.
Unknown as a noun:

Any thing, place, or situation about which nothing is known; an unknown fact or piece of information.
Unknown as a noun:

A person of no identity; a nonentity