I installed Docker in my machine where I have Ubuntu OS.
When I run:

sudo docker run hello-world

All is ok, but I want to hide the word sudo to make more short the command.
If I write the command without the word sudo

docker run hello-world

That displays the following:

docker: Got permission denied while trying to connect to the Docker daemon socket at unix:///var/run/docker.sock: Post http://%2Fvar%2Frun%2Fdocker.sock/v1.35/containers/create: dial unix /var/run/docker.sock: connect: permission denied. See 'docker run --help'.

It has happened the same when I try to make:

docker-compose up

How can I resolve this?