H

heartbeat

A special communication among members of a cluster that keeps all members aware of one another ‚ s existence (and thus their operational state).

HELO

The SMTP command used by one host to initiate communications with another host.

hierarchy

Any structure or organization that uses class, grade, or rank to arrange objects.

hot standby

In this cluster operation mode, a passive node can take on the resources of any failed active node.

HTML

See HyperText Markup Language (HTML).

HTTP

See HyperText Transfer Protocol (HTTP).

HTTP Digest authentication

An Internet standard that allows authentication of clients to occur using a series of challenges and responses over HTTP.

HyperText Markup Language (HTML)

The script language used to create content for the World Wide Web (WWW). HTML can create hyperlinks between objects on the Web.

HyperText Transfer Protocol (HTTP)

The Internet protocol used to transfer information on the World Wide Web (WWW).