With many airlines, you can do the check-in online, before arriving at the airport.
You can also do the check-in at the airport. Many airports have self check-in machines where you can easily do the check-in. At Helsinki Airport, most of the airlines offer the possibility to do the check-in at the self service machines. With some airlines the check-in and handover of luggage are done at the check-in counter by the staff.
When using the self service machine, the passenger is first asked to perform identification. This can be done for example by using a passport or a booking reference number. When the identification is done, follow the instructions the machine gives you for completing your check-in.
If you travel with hand luggage only, the machine will print out your boarding pass. Take it with you to security.
When travelling with checked luggage, the machine will also print out the bag tag along with the boarding pass. Attach the tag to the handle of your luggage and proceed to your airline's bag drop counter.
If you have already checked in online before arriving at the airport and you are travelling with checked luggage, you can print out a bag tag in the self service check-in machine, after which you can take the luggage to your airline's bag drop point.
Once the check-in is done, you got your boarding pass and you have dropped off your luggage, you can proceed to the security control.
Please check more detailed check-in instructions directly from your airline/tour operator.