Since the time docker containers came into picture its being a continuous discussion that who is better among both of them. Here are some points which will give some idea that how docker containers are better as compared to virtual machines.

a)Easy to deploy on local or cloud infrastructure 

Many of the Cloud server providers support docker images which can be easily deployed on the cloud infrastructure which was earlier missing in the VMs.

b)Resource utilization

In VMs we allocated fixed resources to a appliance which sometimes not be useful. For Example, You have setup a VM with 16CPUs which will manage 50000 request/sec but its not a practical situation that it will always generate that much of request. In a time when the requests are low the available CPUs not get utilized but in the case of docker containers it manage the number of CPUs according to its requirement.

c) Easy & Fast Depolyment

As Docker containers are light weighted as it doesn't have any separate operating system so their deployment is easy & less time taking. On comparison if a VM takes few minutes to deploy on the other hand a container can be deployed within seconds.