zabbix-agent and zabbix_get

How to connection Zbbix Server to Zabbix-Agent

# zabbix_get -s xx.xx.xx.xx -k Zabbix-Item-Key

# zabbix_get -s 127.0.0.1 -k agent.version
3.0.4

# zabbix_get -s xx.xx.x.xx -k "proc.num[httpd]"
# zabbix_get -s xx.xx.x.xx -k "net.tcp.service[ssh]"