The: definite article. You use it when you talk about a particular, specific noun. Example: The house around the corner from my house is blue. A/an: indefinite article. You use it when you talk about any noun, no particular one, in a singular way. Example: An elephant is very heavy. A house can be big or small. No article is required when you are talking in a general way about something. Examples: Houses are more comfortable than apartments. Life is sometimes difficult. People are complicated creatures. Love is in the air.

the for something specific a and an for unspecific things