A2 corresponds to the elementary level. According to the CEFR, students at this level...

• Can understand sentences and frequently used expressions related to areas of most immediate relevance (e.g. very basic personal and family information, shopping, local geography, employment).
• Can communicate in simple and routine tasks requiring a simple and direct exchange of information on familiar and routine matters.
• Can describe in simple terms aspects of their background, immediate environment and matters in areas of immediate need.

According to the official CEFR guidelines, someone at the B1 level in English:

• Can understand the main points of clear standard input on familiar matters regularly encountered in work, school, leisure, etc.
• Can deal with most situations likely to arise whilst travelling in an area where the language is spoken.
• Can produce simple connected text on topics which are familiar or of personal interest.
• Can describe experiences and events, dreams, hopes and ambitions and briefly give reasons and explanations for opinions and plans.