Silk and satin are both smooth and soft. Though these two come with somewhat similar features and have a similar look, they are quite different in every sense.
Silk is natural; satin is artificial.
Silk is made from cocoons of silk worms. The fibre is removed from the cocoons and made into threads, which is then woven into clothes.
Satin can be produced from many types of materials like silk, nylon and polyester.
Satin is more delicate than silk and so when handling it, more care is needed.
Silk, which is a natural protein fiber, has a shimmering appearance. The shimmering appearance is because of the prism like structure of its fabric, which refracts the light producing various colors.
Satin has a glossy surface and a dull back. Satin is made of a number of floats (interlacing). It is these floats that give Satin a glossy look and also a smooth surface.
Silk threads are hard to produce, as a single strand of thread requires silk from thousands of silk worms. This makes silk fabrics more expensive than satin.
Silk fabrics can be hand washed using cold water and it is better to avoid too much wringing as it can damage it. Satin fabrics should be dry-cleaned.