Cloud Shell is a small virtual machine running a Linux shell which you access through the browser through the OCI Console. And it comes with a pre-authenticated OCI CLI and lots of utilities like Git, Java, Python, etc.
SSH protocol, also referred to as Secure SHell, is a method for secure remote login from one computer to another.
Shape is basically a (virtual hardware) template which determines number of CPUs, amount of memory, other resources.
Image is basically an operating system, which runs on top of that shape.
(shell)$ mkdir .ssh
(shell)$ cd .ssh
(shell)$ ssh-keygen -b 2048 -t rsa -f mykeyname
(shell)$ sudo yum -y install httpd
(shell)$ sudo systemctl enable httpd.service
(shell)$ sudo systemctl start httpd.service
(shell)$ sudo firewall-offline-cmd --add-service=http
(shell)$ sudo firewall-offline-cmd --add-service=https
(shell)$ sudo systemctl enable firewalld
(shell)$ sudo systemctl restart firewalld
(shell)$ sudo bash -c 'echo This is my web server running on Oracle Cloud Infrastructure >> /var/www/html/index.html'
(shell)$ ssh -i demokey opc@<publicIPaddress>