While dealing with circuit boards, there will be instances where you come into contact with sensitive electronic components. To protect against damaging those components, electrostatic discharge (ESD) protection equipment should be used when handling those components. Solutions requiring ESD Precautions will be marked with the following precaution: 

Warning: This is an ESD sensitive process. A grounding strap MUST be worn for this process, due to the handling of circuitry. For more information, click here.

Clicking that link will bring you to this page. 

A full ESD protection kit includes the following items:
  • ESD protection mat
  • Cable (ESD mat ground)
  • ESD wrist strap (includes a coilded cable with removable alligator clip)
  • USB flash drive (unrelated to ESD protection)

For most solutions, you will only need the ESD wrist strap and ESD mat ground cable (this cable can unsnap from the ESD protection mat). The ESD protection mat is only used for certain maintenance/repair operations done directly on circuit boards.

When prompted by the precaution shown above, take the following steps:

Put on the ESD wrist strap, and adjust the strap if needed. The strap should make good contact with your skin.
If the coiled wrist strap cable is not already attached to the wrist strap, snap it into place.
Plug the coiled wrist strap cable into the ESD mat ground cable. Remove the alligator clip if needed.
Plug the ESD mat ground cable into a grounded outlet.

The order of these steps is not important, but they must all be carried out to ensure you are grounded before handling sensitive electronic components.