Numbers is a spreadsheet application developed by Apple Inc. as part of the iWork productivity suite alongside Keynote and Pages. Numbers 1.0 was announced on 7 August 2007 and thus it is the newest application in the iWork suite. Numbers runs on Mac OS X v10.4 "Tiger" or newer. On 27 January 2010, Apple announced a new version of Numbers for iPad with an all new touch interface.

Numbers uses a free-form "canvas" approach that demotes tables to one of many different media types placed on a page. Other media, like charts, graphics and text, are treated as peers. In comparison, traditional spreadsheets like Microsoft Excel use the table as the primary container, with other media placed on it. Numbers also includes features from the seminal Lotus Improv, notably the use of formulas based on ranges rather than cells. However, it implements these using traditional spreadsheet concepts, as opposed to Improv's use of multidimensional databases. Numbers also includes numerous stylistic improvements in an effort to improve the visual appearance of spreadsheets. At its introductory demonstration, Steve Jobs pitched a more usable interface and better control over the appearance and presentation of tables of data.

A number is a mathematical object used to count and measure. In mathematics, the definition of number has been extended over the years to include such numbers as zero, negative numbers, rational numbers, irrational numbers, and complex numbers.

Mathematical operations are certain procedures that take one or more numbers as input and produce a number as output. Unary operations take a single input number and produce a single output number. For example, the successor operation adds one to an integer, thus the successor of 4 is 5. Binary operations take two input numbers and produce a single output number. Examples of binary operations include addition, subtraction, multiplication, division, and exponentiation. The study of numerical operations is called arithmetic.

A notational symbol that represents a number is called a numeral. In addition to their use in counting and measuring, numerals are often used for labels (telephone numbers), for ordering (serial numbers), and for codes (e.g., ISBNs).

Computer software, or just software, is a collection of computer programs and related data that provides the instructions for telling a computer what to do and how to do it. Software refers to one or more computer programs and data held in the storage of the computer for some purposes. In other words, software is a set of programs, procedures, algorithms and its documentation concerned with the operation of a data processing system. Program software performs the function of the program it implements, either by directly providing instructions to the computer hardware or by serving as input to another piece of software. The term was coined to contrast to the old term hardware (meaning physical devices). In contrast to hardware, software "cannot be touched". Software is also sometimes used in a more narrow sense, meaning application software only. Sometimes the term includes data that has not traditionally been associated with computers, such as film, tapes, and records.