Dedicated servers are used to power complex applications and high-traffic websites. You might also opt for one if you serve a large quantity of media, such as high-resolution images, audio files, and streaming video clips, or you see very high levels of traffic (or perhaps both are applicable). Dedicated hosting also provides the highest level of security and server customization possible. Also see: Colocation.
When a website has been secured with an SSL certificate, a visitor will see a padlock icon in their web browser and they’ll be connected to the site using the https:// protocol. With the SSL certificate in place and the user accessing the site through https, the connection between the browser and the web server has been secured and sensitive information can safely be transferred.
The availability of a website is measured by the percentage of a year in which the website is publicly accessible and reachable via the Internet. This is different from measuring the uptime of a system. Uptime refers to the system itself being online. Uptime does not take into account being able to reach it as in the event of a network outage. A hosting provider's Service Level Agreement (SLA) may include a certain amount of scheduled downtime per year in order to perform maintenance on the systems. This scheduled downtime is often excluded from the SLA timeframe, and needs to be subtracted from the Total Time when availability is calculated. Depending on the wording of an SLA, if the availability of a system drops below that in the signed SLA, a hosting provider often will provide a partial refund for time lost. How downtime is determined changes from provider to provider, therefore reading the SLA is imperative. Not all providers release uptime statistics. Most hosting providers will guarantee at least 99.9% uptime which will allow for 43m of downtime per month, or 8h 45m of downtime per year.
Migration or transfer services are often free or offered at a reasonable fee. These services help move your existing site to the new hosting provider. They can save a huge amount of hassle. Just remember that the migration process is often automated, and may fit in with the host's processes and needs rather than yours. Not everything may migrate, and you may find the organization of the newly migrated site makes for harder maintenance in the long run.