What data can I enter in a cell in Excel 2007?

A cell can hold any of the three basic types of data namely numbers, text, and formulas.
Numbers – You can enter numbers with fractional and without fractional parts. Date, or time entered in a cell is also treated as number. By default, the numbers are aligned to the right.
Text – Any string that you enter or a number preceded by an apostrophe (e.g., ‘123) is treated as text. By default, text is aligned to the left.
Formulas – Formulas performs calculations and returns a result. You enter a formula by typing the equals sign and then completing the syntax for the formula. If the result returned is a number then it will be aligned to the right and if the result is text value then it will be aligned to the left.