Originally Posted by DeltaOneFlyer

both Airport counter VOA and eVOA will get you a small sticker on your passport.

If you do airport counter VOA, you first have to line up to pay for the VOA at one counter, then take the receipt of your payment and line up again at the immigration clearance counter to get the sticker (which is basically the arrival stamp) and then be let in the country.
If you get the eVOA in advance, you get to skip the first counter and line up directly at the immigration clearance counter and then get your sticker and be let in the country.

Hope that clarifies things. And dont forget to also do your customs clearance in advance, which is after the immigration clearance.