When it comes to design, contemporary and modern are not interchangeable terms.
The Short of It:
Modern design refers to design from the Modern Movement, a specific period in design history that lasted from around 1920 to 1950 and included a number of designers who are today considered iconic, such as Charles and Ray Eames, Hans Wegner, Alvar Aalto, and Mies van der Rohe. The Modern Movement in design stressed simplicity, function, and accessibility, among other values, while rejecting unnecessary or excessive ornamentation, as well as luxury for its own sake.
Contemporary design refers to work that is temporally current-- that is, design that’s being created today or in the recent past. Often, contemporary design can be credibly described as modern, in that--as is often the case--it’s been influenced by the ethos of the Modern Movement or Modernist designers. By contrast, Modern design, strictly speaking, can’t be called contemporary.
So, when you call a chair or a table “modern,” what you’re saying is that it’s either designed by a designer who associated with the Modern Movement, or that it exhibits qualities associated with the Modernism. By contrast, when you call a chair or a table “contemporary,” all you’re saying is that it was designed recently.
The Long of It:
Function Should Dictate Form: The Central Tenet of the Modern Movement
The Modern Movement in architecture and design was a reaction to the perceived decadence of styles from the 19th century. It established utility, simplicity, and functionality as ideals towards which design should strive, and, in certain interpretations, went so far as to insist that designers have a moral responsibility to design products of quality that could themselves improve society. Modernism grew in tandem with the capability for industrial mass-manufacturing, something that many Modernist designers used to further their belief that design should be democratic: mass-manufacturing gave designers such as Charles and Ray Eames (proponents of the idea that everyone should be able to enjoy good design) the opportunity to bring their designs to market at an accessible price-point.
With its emphasis on simplicity and function, and its rejection of superfluous ornamentation, it’s clear how the modern movement influenced subsequent design movements-- minimalism, for instance.
Contemporary design and architecture has been hugely influenced by Modernism-- more so than any other movement in design history, arguably. When you examine the work of distinguished contemporary furniture and industrial designers such as Jasper Morrison, Konstantin Grcic, or Naoto Fukasawa, it’s impossible not to notice features derived from the Modernist Movement. (Our work at 57st. design--by our own admission--draws heavily from the Modernist movement, both its ideology and its visual forms.) To be clear, though, contemporary design doesn’t necessarily draw from Modernism exclusively.
So remember: when you're talking about design, contemporary does not equal modern.