Internet server monitoring is much wider than website monitoring. Monitoring a web server means that the server owner always knows if one or all of his services go down. Web server monitoring may be internal, i.e. web server software checks its status and notifies the owner if some services go down, and external, i.e. some web server monitoring companies check the services status with a certain frequency. External monitoring is much more reliable, as it keeps on working when the server completely goes down.
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