# Lets know more about docker

So firstly docker is an open source platform . It helps the users to build deploy run update and mannage containers. So now a question might pop that what accutually is container ? Conatiner is a standard unit of software that packages code and all its dependencies so that the application runs quickly and reliably from one computing environment to another. A Docker container image is a lightweight standalone executable pakage of software that includes everything needed to run an application . Means it contains code , runtime, system tools , system libraries and settings.Available for both linux and windows based application containerized software will always run the same regardless of the infrastructure.

While studing about docker one question striked my mind is that what problem did this docker solved ?  and the answer to this question is that it solved the problem of missing or incorrect application dependenceis such as libraraies, interpreters, code etc. So what docker does is that it creates one single machine and all the containers run in that single virtual machine so by taking this approach the overhead of running a virtual machine is fixed while the number of conatiners can scale up .