You may or you may not know the name: Futura, but you know the typeface. Futura’s letterforms take their cues from geometric shapes. The O is wide and round, practically a perfect circle, and the A has a knife sharp apex. The lowercase letters have a low x-height and the ascenders are so tall they rise noticeably far above the cap line. Its futuristic feel comes from the simplistic elegance of the way each letterform appears to have been built. It looks as though the designer simply took a circle, and used that for the O, then took a smaller circle, added a stem to the side of it and called it an a. Look at the black O G a N V above to see what I mean. However, part of Futura's genius is the fact that many of the letterforms are not actually made of the shapes they imitate.
Now look at the red and yellow letters, zoom in to look a little closer if you need. Notice how the red O does not match up with the yellow circle? The red G curves inward rather than following the path of the yellow G, which was made out of a perfect circle and a line. The lowercase a is not simply a circle with a stem on the side, the counter (hole) inside it cuts into the stem too. The points at the top and bottom of the N and the V extend far below the base and cap line. These are just some examples from the typeface, but they beg the question: Why would the designer make these subtle changes, that are almost impossible to notice until they are pointed out to you? 
Typography is the art of using the letterforms to communicate with the eye and the brain on a subconscious level. This allows designers to access a library of associations that we build up through experience of our environment, and convey an emotion or trigger a thought, before any words have even been said. Sarah Hyndman made this point much better than I am now in her excellent TED talk: https://www.youtube.com/watch?v=OXc-VZ4Vwbo. One of the really interesting parts of her talk is where she shares an experiment she conducted with a previous audience. She gave everyone two identical jellybeans. The first jellybean was eaten while the audience were shown the font on the left (below), and the audience voted it 17% sweeter. The second was eaten while the audience looked at the typeface on the right, and they voted it 11% more sour. 
In the case of Futura, the aim is difficult to pin down due to its versatility, but often it attempts to convey modern, minimalistic elegance. The exact geometric shapes that were adjusted for the typeface, while attractive in their simple, satisfying symmetry are not close enough to the brain's past memories of the shapes of the letterforms. This is why the letters cannot follow the exact geometric forms, because the eye will perceive them as unbalanced. It's the same reason the X in Helvetica is not symmetrical. The red X is Helvetica, the yellow is a perfectly symmetrical X. It's a very subtle difference, but at the wrong size, the yellow x would look imbalanced, as if it were falling over slightly, so the designers balanced it out by leaning it the other direction. Even though people may not consciously notice these issues, the eye and the brain can interpret them, and this is why some typefaces become so popular. The designer can be sure that they are not subconsciously offending the viewer of the type, and therefore be confident in the design. Futura has succeeded in this for 90 years, and as you will see: it is unbelievably popular, and has a very interesting history.
Futura was designed in 1927, yet is has managed to stay a powerful tool in a designer’s arsenal, and remained relevant and popular for 90 years. Oh, and in case you couldn't tell, this post is not written in Futura. 
Historically, it is a typeface of huge importance. It was the first typeface to go to the moon - on a plaque that was left by the astronauts, as a commemoration of man’s achievement.
Futura has even had a dispute with the Nazis. The typeface was designed by Paul Renner, a legendary German designer, and also the author of ‘Kultur-bolschewismus’, an 1932 essay that was very critical of the Nazi’s cultural policy. Renner was exiled to Switzerland, and the Nazis waged war on modern art and design. Meanwhile, the Bauhaus design school, whose modern philosophy Renner was a big advocate of, was shut down. Futura was a symbol of the future, and that was not acceptable. The Nazis were traditionalists, and the now quite popular Futura was being phased out. The Nazis preferred the style present in ‘Fraktur’ an old-fashioned blackletter font, which was another of their ways of telling the world exactly where they wanted to take Germany.
This did not work out. Fraktur was far too hard to read, and became massively impractical. It became clear that if they were to be a world superpower, the Nazis needed to embrace modern typography. But by the time they had come around to Renner’s ideas of an “eminently German” typeface, it was already internationally renowned. The Nazis began to embrace Futura in 1941, claiming Fraktur was a ‘Jewish style’, but the chance to showcase to the world an internationally recognised masterpiece that would remain in such high regard 90 years later had been missed.  
Futura was central to the artist Barbara Kruger's work (above), which was clearly the inspiration for the Supreme logo. The use of the type face looks fantastic in both, but there have been plenty of legal disputes over who copied who. 
Futura's influence on graphic design today is massive. The success of the typeface is evident in its use by some of the most successful brands in the world. All of the logos below make up just a small selection of logotypes either using a version of, or inspired directly by Futura.
Sources: Vox Almanac, Sarah Hyndman TED Talk: Wake up and smell the fonts, Fontmeme.com, Sessions.edu