Different forms of same languages are called dialect.
one official language is English

Dialects and Official Languages
A dialect is a form of a language spoken in a particular region or by a specific group of people. It differs from the standard language in terms of vocabulary, grammar, and pronunciation. Dialects can develop due to geographical isolation, social class, or cultural factors. They are often mutually intelligible with the standard language but may have unique features that set them apart.

Official Languages
There are 195 countries in the world, each with its own set of official languages. The number of official languages varies from country to country, with some having only one official language while others have multiple. For example, the United States has English as its official language, while Switzerland has four official languages: German, French, Italian, and Romansh.
In total, there are 6,909 living languages spoken around the world. Out of these, 23 languages have official status in more than one country. The most widely spoken official language is English, followed by French, Spanish, Arabic, and Chinese.
Having multiple official languages can promote cultural diversity and inclusivity within a country. It allows people from different linguistic backgrounds to communicate and participate in society. However, it can also present challenges in terms of governance, education, and public services.
In conclusion, dialects are variations of a language spoken in specific regions or by certain groups, while official languages are designated languages used by governments for communication and legal purposes. The number of official languages varies globally, reflecting the linguistic diversity of different countries.