SUMMARY

All speakers of English can talk to each other and pretty much understand each other. Some differences are the result of age, social siuation and where and when the language was learn. These differences are reflected in the pronunciation of words and grammatical rules.
A dialect is not inferior or degraded from of language, and logically could not be so, because a language is a collection of dialects.

A dialect si when a group of people or and area speak in a different way, their own way. and Idiolect is when every person ha sa unique way of speaking. The dialects of a language are the mutually intelligible form of that language that differ in systematic ways from each other. Dialects develop because languages have changed, and the changes that occur in a group or an area may differ from those that occur in another.

For that reason develop regional and social dialects. some differences in United States, regional dialects may be traced to the dialect spoken by colonial settlers from England. And social dialects arise when groups are isolated socially such as; American of African (descent in the U.S) and African American English which is distinct from the dialects spoken by non-Africans. Rather dialects merge into each other, forming a dialect continuum. A movement toward greater uniformity and less variation among dialects.
And a regional phonological or phonemic distinctions are often referred to a different accents. The study of regional dialects has produced dialect atlases. In many countries a dialect or idiolect is viewed as the standard, such as Standar American English (SAE). But this particular dialect is not linguistically superior.

Some non-standar dialects are deficient, as a erroneously suggested regarding African American English. A study shows it to be as logical, complete and expressive as any other dialect. One latino dialect spoken in Southwest, referred to as Chicano English (ChE), shows systematic phonological and syntactic differences from SAE that stem from the influence of Spanish.
This dialect is acquired as a first language by many children. It is not English with a Spanish accent but, like African American English, mutually intelligible dialect that differs systematically from Standard American English.