What is an 'expression' in Access?

An 'expression' in Access fundamentally refers to a combination of values, fields, functions, or operators that, when evaluated, produces a specific value. Expressions are essential in Access for performing calculations, manipulating data, or specifying criteria for queries. For instance, if you have a field containing numbers and you want to calculate the total or average, you would use an expression like "Sum([FieldName])" or "Avg([FieldName])". This capability to create complex calculations or derived values from existing data is what distinguishes expressions in the context of Access.

The other options describe different features or functionalities related to Access but do not accurately define what an expression is. For example, establishing new tables or importing data involves different functions and commands, and statements for data retrieval pertain to structured query language (SQL) or query design rather than expressions themselves. Thus, the focus on the combination of elements leading to a value is what makes the definition distinct and correct.