Values are distinguished by the ability to have a mathematical function applied to them. Thus, you can add or multiply 2 and 2. Numbers are usually left justified in the cell. Labels are things which cannot be used in a mathematical function. Generally speaking, the spreadsheet assumes that letters denote a label and numbers denote a value.
Labels appear on the right side of a cell.
A formula is a mathematical formula. There are, however, a few more formulae than adding, multiplying, dividing and subtracting. There are three parts to this formula. The second part of the command is the part that tells the computer exactly what it is you want it to do. This tells the computer that you what the sum of something.