Typical Zabbix hosts are the devices you wish to monitor (servers, workstations, switches, etc).
Creating hosts is one of the first monitoring tasks in Zabbix. For example, if you want to monitor some parameters on a server "x", you must first create a host called, say, "Server X" and then you can look to add monitoring items to it.
Hosts are organized into host groups.
Proceed to creating and configuring a host.