According to the guidelines put forth in the Framework, these language levels can be broken down to three categories: the A level represents a “basic user” of a language, able to answer simple and direct questions put to them such as what time it is, introduce themselves and talk about their family in a basic manner, and so on. This level generally assumes that the user of the language will regularly need help or prompting from native speakers.
The B level represents an intermediate or independent user of a language – this kind of user might not need as much prompting from native speakers, and can give reasons and explanations in the language they are trying to use, but might still need correction on the finer points of grammar, idiomatic usage, slang, and regional variation. A C level user is marked with proficiency in both spoken and written forms of a language, recognize implicit meanings, and can express ideas spontaneously, even if on a topic they are not already interested in.
These abbreviations indicate levels of the Common European Reference Framework (CEFR), a way to standardize language learning and teaching across Europe, no matter which language. According to the Framework, the principles behind this is to “improve the quality of communication among Europeans of different language and cultural backgrounds… this is because better communication leads to freer mobility and more direct contact, which in turn leads to better understanding and closer co-operation”