Lecture says when you start an instance then the following happens —OS boot, bootstrap scripts, application start.
Should it not say when we launch an instance, since bootstrap scripts only run when launching
or it bootstrap scripts should be removed when we are talking about start.
Could the issue here be one of language? The language around launching, starting or running instances can be a little confusing. The AWS API call to launch instances is
run-instances see https://awscli.amazonaws.com/v2/documentation/api/latest/reference/ec2/run-instances.html
You are, generally correct. Default behaviour is that when an instance is first launched, the sequence of events is broadly as you describe: OS boo, bootstrap script, application start. When an instance is subsequently restarted (i.e. started, but not on the first occasion), then the bootstrap script is not re-executed.
user-data can be configured to be executed on every boot of the instance, see https://docs.aws.amazon.com/AWSEC2/latest/UserGuide/user-data.html#user-data-shell-scripts In my opinion (from what I’ve read), this specific configuration is out of scope for the Certified Cloud Architect Associate exam.