Traditionally when you hear someone say 'Our website is Secure' they imply that their website uses SSL (Secure Sockets Layer) and that the traffic is encrypted (The little lock in your browser usually appears) unfortunately Encryption doesn't make a website secure.

High availability (HA) is a characteristic of a system, which aims to ensure an agreed level of operational performance, usually uptime, for a higher than normal period.
Modernization has resulted in an increased reliance on these systems. For example, hospitals and data centers require high availability of their systems to perform routine daily activities.

What’s the big fuss about website optimization tools and why do you need them?
Simply put, website optimization tools help to automate the process of making your website more visible to search engines in addition to making them more likely to convert.