Websites or apps not working earlier? Here's why

NEW YORK (WABC) -- A more than four-hour outage with one of the country's biggest Internet host providers Tuesday caused websites and apps to stop working in the eastern United States.

Internet users started reporting problems with online services that utilize Amazon Web Services S3 servers just before 1 p.m. Sites and apps tied to the cloud-based services were inaccessible and many gave an error message.

AWS posted this message on Twitter:

The online service, based in Virginia, reported "high error rates" with its S3 service in the East Coast region.

Services were fully restored just after 5 p.m., according to Amazon.

The server outage impacted websites like Slack, Trello, Quora, IFTTT and many others. Services like remote access to Nest thermostats also was affected.

The problem affected both "front-end" operations -- meaning the websites and apps that users see -- and back-end data processing that takes place out of sight.

Since some sites and services may only use AWS for parts of their sites or apps, certain features of a site like photos or video may not have loaded during the outage.

The outage even impacted a website that checks and shows the status of other sites that may be down, isitdownrightnow.com: