[sokoloff]

AWS RIs don't require upfront purchasing (payment). They offer full-upfront; they offer half-upfront; they also offer no-upfront.

Source: https://aws.amazon.com/ec2/pricing/reserved-instances/pricin...

[manigandham]

Yes, but it's still upfront purchasing. You don't have to pay immediately but you have to commit to the full term to get the discount, with an option to get more of a discount if you pay early too.

Google's sustained-use discounts have no commitments at all.