What is the difference between between a metaphor and a simile?

Metaphors and similes are easily confused! Both are methods of description that compare one thing to another. We find them all types of writing but most of all in poetry and fiction prose. A simile using words like: 'as' and 'like' to compare one thing to another. for example:
His hair looked like yellow candyfloss.
On the other hand, a metaphor will make a direct comparison stating that one thing is another. For example:
She had a heart of gold.