A physical server wholely utilized by a single customer. You have to guess your capacity and need to overpay for underutilize servers. You cant vertically scale and need manual migration. Replacing a server is very difficult. Multiple apps can result in conflicts in resource sharing.

BUT!! You have a gurantee of security privacy & full utility of underlaying resources.

We can run multiple VM on one machine. Hypervisor is the software that handles/manages the VM Guest Operating Systems. Physical Server Shared by multiple customer. You need to pay a fraction of Capital Expenditure as compared to 🔗Dedicated Hosts. You still will overpay for underutilized VM.

NOTE #1 : Multiple Applications on Same VM will cause conflicts in resource sharing. But It is much easier to export/import images for migration

NOTE #2 : Easier to vertically and horizontally scale.

VM running multiple containers. Docker Daemon is the name of the software layer that lets you run multiple containers You can maximize the utility of available capacity, which is more cost-effective, than multiple VMs. Multiple apps can run side-by-side without being limited to some OS requirement & will not cause conflicts during resource sharing.

They are managed VM running managed containers. You upload a piece of code. You are responsible to select the amount of memory, duration and the type of runtype. Only responsible for Code + Data. Very Cost Effective, only pay for the time the code is running. NOTE: Cold Start is a side-efffect of serverless.