Conjunctions are of three kinds:
Coordinating Conjunctions
Subordinating Conjunctions
Correlative Conjunctions
Coordinating Conjunctions- There are many coordinating conjunctions we may use, like- for, and, nor, but, or, yet, so. These may be memorized using the mnemonic FANBOYS. Each letter in the word, corresponds with a different conjunction. Coordinating conjunctions link 2 sentences which share a common value. Eg. Ram goes to school. Ali goes to school. Correct use of conjunctions: Ram and Ali go to school. This is a blue pen. She is a a woman. Incorrect use of but: This is a blue pen but she is a woman. (No common value, i.e. the nature of both subjects is different) This is a blue pen. This is a red pen. Correct use of but: This is a blue pen but this a red pen. E.g.: I’d like pizza or a salad for lunch. We needed a place to concentrate, so we packed up our things and went to the library. Jesse didn’t have much money, but she got by.  
Subordinating Conjunctions- Subordinating conjunctions join independent and dependent clauses. A subordinating conjunction can signal a cause-and-effect relationship, a contrast, or some other kind of relationship between the clauses. Common subordinating conjunctions are because, since, as, although, though, while, and whereas. Sometimes an adverb, such as until, after, or before can function as a conjunction. I can stay out until the clock strikes twelve. Here, the adverb until functions as a coordinating conjunction to connect two ideas: I can stay out(the independent clause) and the clock strikes twelve (the dependent clause). The independent clause could stand alone as a sentence; the dependent clause depends on the independent clause to make sense. The subordinating conjunction doesn’t need to go in the middle of the sentence. It has to be part of the dependent clause, but the dependent clause can come before the independent clause. Before he leaves, make sure his room is clean. If the dependent clause comes first, use a comma before the independent clause. I drank a glass of water because I was thirsty. Because I was thirsty, I drank a glass of water. Subordinating Conjunctions
Correlative conjunctions- are pairs of conjunctions that work together. Some examples are either/or, neither/nor, not only/but also,  and/so, Not only am I finished studying for English, but I’m also finished writing my history essay. I am finished with both my English essay and my history essay.
Source:https://www.peptalkindia.com/the-many-functions-of-conjunctions/  

Conjunctions are of three kinds.

1. Coordinating Conjunctions
2. Subordinating Conjunctions
3. Correlative Conjunctions

Coordinating Conjunctions
There are many coordinating conjunctions we may use, like- for, and, nor, but, or, yet, so. These may be memorised using the mnemonic FANBOYS. Each letter in the word, corresponds with a different conjunction.
Coordinating conjunctions link 2 sentences which share a common value.
Eg.

1. Ram goes to school.
2. Ali goes to school.

Correct use of conjunctions: Ram and Ali go to school.

1. This is a blue pen.
2. She is a a woman.

Incorrect use of but: This is a blue pen but she is a woman. (No common value, i.e. the nature of both subjects is different)

1. This is a blue pen.
2. This is a red pen.

Correct use of but: This is a blue pen but this a red pen.
E.g.:
I’d like pizza or a salad for lunch. We needed a place to concentrate, so we packed up our things and went to the library. Jesse didn’t have much money, but she got by.
 
Subordinating Conjunctions
Subordinating conjunctions join independent and dependent clauses. A subordinating conjunction can signal a cause-and-effect relationship, a contrast, or some other kind of relationship between the clauses. Common subordinating conjunctions are because, since, as, although, though, while, and whereas. Sometimes an adverb, such as until, after, or before can function as a conjunction.
I can stay out until the clock strikes twelve.
Here, the adverb until functions as a coordinating conjunction to connect two ideas: I can stay out(the independent clause) and the clock strikes twelve (the dependent clause). The independent clause could stand alone as a sentence; the dependent clause depends on the independent clause to make sense.
The subordinating conjunction doesn’t need to go in the middle of the sentence. It has to be part of the dependent clause, but the dependent clause can come before the independent clause.
Before he leaves, make sure his room is clean.
If the dependent clause comes first, use a comma before the independent clause.
I drank a glass of water because I was thirsty. Because I was thirsty, I drank a glass of water.
Subordinating Conjunctions
Correlative conjunctions are pairs of conjunctions that work together. Some examples are either/or, neither/nor, not only/but also,  and/so,
Not only am I finished studying for English, but I’m also finished writing my history essay. I am finished with both my English essay and my history essay.
Source: https:https://www.peptalkindia.com/the-many-functions-of-conjunctions/