What do you call the different ways of speaking in one and same language?

There are several terms you can use to describe the different ways of speaking in one and the same language, depending on what aspect you're focusing on:

General terms:

* Dialect: This is the most common term, referring to variations in pronunciation, vocabulary, grammar, and syntax within a single language.

* Variety: A broader term than "dialect," encompassing any variation in language, including regional, social, and functional differences.

* Register: This refers to the style of language used in a specific context, such as formal or informal speech, or technical jargon.

* Accent: This refers specifically to variations in pronunciation.

More specific terms:

* Sociolect: A variety of language used by a particular social group.

* Ethnolect: A variety of language used by a particular ethnic group.

* Idiolect: The unique way in which an individual speaks.

* Slang: Informal words and phrases used by a particular group.

* Jargon: Specialized vocabulary used by a particular profession or group.

The specific term you choose will depend on the particular aspect of language variation you want to highlight. For example, you might talk about the "dialects" of English spoken in different regions of the United States, or the "registers" of formal and informal speech in English.