How can colons ":" be used as a separator?

The colon in English grammar is a punctuation mark, which consists of two dots of same size centered and placed on a same vertical line. A colon is at the beginning of an enumeration or an explanation or a list. Besides the use in English language, the colon is also used in computing whilst writing computer programming or in mathematical terms.A colon is most commonly used with titles ratios and subtitles of books, city and publishers in bibliography or in between chapter and verse in biblical citations. Colon is also used for salutations in business letter and any other formal purpose such as letter writing or emailing. The most frequent and most common use of colon is made to separate the hours and minutes while mentioning time in written. Following are the areas where colons are used as a separator.

Colon as a separator

Syntactical descriptive- In this sense, a description is introduced by the colon. Precisely it makes the elements in a set explicit.

Example- I have four brothers: X, Y, Z and A

-I have two puppies: Daniel and Donny.

Syntactical descriptive colons are majorly used in separating the numbers representing seconds, minutes and hours in abbreviated measures of time.

Example - The show will end at 8.00 pm.

You will need to depart by 14.30.

Using colon as a separator is very frequently used to separate the numeric representing the hours, minutes and seconds of time while presenting in written format.

A colon is used in descriptive location of a verse in a book as well. The verse are separated in a book using colons if the book is divided into verses. Bible and Quran to name a couple are examples of such books, whichare divided in verses.

Example- "Isaiah 52:8"
"Deuteronomy 37:39"
"Quran 10:15"

Appositive- to separate the title of a work from its principal title an appositive colon is used. This is yet another example where the colon is used as a separator. While giving a title neither of the two part needs to be explanatory in sense of a complete sentence as if tittles titles do not represent the expository writing. Thus, colons are used to separate the two subtitle and the principal title separately.

Example- Star Wars Episode VI: Return of the Jedi   

Star Wars Episode IX: The Rise of Skywalker

Segmental- Similar to a quotation mark or dash a segmental colon is also used in the introduction of speech. This form is still used while writing dialogues such as in play. When using segmental colon in in dialogues it separates the content of the dialogue from who is delivering the dialogue. Besides the scope of dialogues and plays, segmental colon is also used to separate speech and the speaker while representing conversation in written format.

Example- Patient: Doctor, I feel pain in my hand.
Doctor: Do not worry! Let me have a look first.
Patient: Sure! Doctor.
Doctor: Thank you.