Topekole,
That is asking a lot, switch's and Relays can take on many different shapes and sizes some of which may not look like a normal relay, usually in a box with more than two lead connections.
when I put the word relay in google images I only saw a couple of types of relays, there are more than thousands of other types and styles.
https://www.google.com/search?q=relay&source=lnms&tbm=isch&sa=X&ved=0ahUKEwjw7LqKsIbfAhVHIDQIHeMZAIAQ_AUIDygC&biw=1225&bih=858
relays are just switches which are controlled by a magnetic coil or some other means to open or close a set of contacts (switches) the silver is on the contact points of the switches, so where there is a need to close a switch remotely or with a smaller current you will find relays, on circuit boards to the solenoid on the starter of your truck (which does not have silver involved in the contact which is just a copper washer and heavy copper lugs for the contact ( the low voltage and very high current would weld the contacts if silver was involved here.(I added this just so you do not go out and destroy your trucks starter to find out there is no silver in the starters relay {solinoid}).
motor contactors are just big relays.
https://www.google.com/search?biw=1225&bih=858&tbm=isch&sa=1&ei=0o0GXKG4D7uT0PEP3KKTyA0&q=contactor&oq=contactor&gs_l=img.12..0j0i67l4j0l3j0i67j0.1088459.1093909..1098458...0.0..0.100.698.8j1......0....1..gws-wiz-img.....0.76J5sFiRxT0