DNA is found in the nucleus of cells, where proteins allow the strands of chromosomes to coil and then super coiling it so it'll be compact.
DNA strands are also twisted, this shape is called the 'double helix'.
DNA has two strands of nucleotides as seen in the diagrams below.
[ONLINE] Available at: http://ocw.mit.edu/courses/biology/7-60-cell-biology-structure-and-functions-of-the-nucleus-spring-2010/7-60s10.jpg. [Accessed 15 March 2015].