DevOps

what is it?

• set of tools, that automate and integrate the processes between software development team and IT teams.
• Delivery
• Automation
• improving the Quality
• continuous Monitoring
• continuous Testing

ok, but why?

• for automating the testing
• for faster delivery

SDLC - Software Developer Life Cycle

• its a structural process of design, building, developing and maintaining of software.
• it contains of distinct phases each responsible for different phase of the development of the software.

so, basically Dev-ops engineer will make sure the 

Building ----> Testing ----> Deployment

is automated and not manual.(usually dev-ops part)

Virtual Machines

• is a compute resource that uses software instead of physical computer to run programs and deploy apps.
• a machine that uses resource that are on another computer, thinking it as its own.
• basically there is a host(the computer with the physical resource) machine and then the guest(the computer which is on the host machine)
• providing a logical isolation.

Hypervisor

• is a virtual machine monitor (also known as VMM).
• is a software that creates and runs VMs.
• it allows one host machine to have multiple VMs by virtually sharing resource, like memory and processing.

AWS (Amazon Web Services)

• is cloud computing platform offered by Amazon where, it provides required resources.
• they a build a physical server or data centers, that provides a VM(EC2 i.e. in AWS) with specified computing, databases and servers.
• users can only interact it with online.

EC2: Virtual servers for running applications.
S3: Object storage for files and media.
RDS: Managed relational databases.
Lambda: Run code without managing servers.

CLI - Command Line Interface is a text-base tool used to interact with the computer using command lines