The screening process at the security checkpoints in the Varadero Juan Gualberto Gomez International Airport is similar to most other airports in the world.
Security checkpoint on ARRIVAL:
After exiting the Immigration/Customs booth you enter the Security Checkpoint area where you and your carry-on baggage are scanned in the x-ray machine and metal detector arch to check if you are entering in Cuba any prohibited or restricted items.
All checked baggage are also being scanned (in another area) and sniffed by drug-sniffing dogs. In the ADUANA CUBA website (Cuban Customs official website), section --Passengers / At the Arrival--, you will find all information on what travelers are allowed to carry on entry.
Then proceed to the baggage carousel to collect you baggage. Keep your passport, tourist card and baggage claim tags handy, you may have to show them when exiting the baggage claim area.
If you have nothing to declare then proceed to the Exit doors. The Exit Customs Officers will checked if your bags was marked (after X-ray scanning) to be manually checked (only if they suspect something).
Security checkpoint on DEPARTURE:
After you've checked-in at your airline's check-in counter, and went through the Passport Control Booth, you will then reach the Security Checkpoint.
Your carry-on bag will be scanned (X-ray machine with conveyor belt) and you will have to walk through the metal detector arch, as in any other airport before boarding. In Cuban airports it's usually not required to remove your shoes, unless you've been ask to do so.
Check the Aduana Cuba website, section --Passengers / At the Departure-- to learn more about what you are allowed to export legally from Cuba as a visitor.