"Although" is a subordinating conjunction in English that introduces a concessive clause, which means it is used to introduce a fact or statement that contrasts with the main clause of the sentence. It is often used to present a situation that might seem to contradict the main idea, but does not negate it. The word "although" can be used at the beginning of a sentence or within it, and it is followed by a subject and verb.

Here is an example to illustrate its usage: "Although it was raining heavily, we decided to go for a walk." In this sentence, "Although it was raining heavily" is the concessive clause that sets up a contrast to the main clause, "we decided to go for a walk." Despite the rain, the decision to go for a walk stands as the primary focus of the sentence.

Another example: "She passed the exam although she had not studied much." Here, the concessive clause "although she had not studied much" provides a contrasting idea to the main clause "she passed the exam," indicating that passing the exam happened despite her lack of preparation.

In summary, "although" is a versatile word that helps to convey a sense of contrast or concession in a sentence. It allows writers and speakers to present information in a nuanced way, acknowledging opposing facts while still emphasizing the primary point. By using "although," you can create more complex and interesting sentences that reflect the multifaceted nature of real-life situations.