Cisco IOS: modes and running vs startup
IOS is modal: user EXEC (>), privileged EXEC (#), then global config (config)# and sub-modes like interface config. You edit the running-config live and must 'copy running-config startup-config' (write memory) to survive a reboot. 'show' commands read state; 'configure terminal' enters config.
Junos: candidate config, commit and rollback
Junos is the opposite philosophy: you edit a candidate configuration that changes nothing until you 'commit'. That makes changes atomic and reviewable ('show | compare'), and 'rollback' plus 'commit confirmed' give safe, reversible changes - no separate 'save' step, and no half-applied config.
MikroTik RouterOS: the internet edge
RouterOS (WinBox GUI, CLI, or API) configures interfaces, addresses, routes, DHCP and firewall/NAT. The classic edge recipe: an address on each interface, a default route to the ISP, a DHCP server for the LAN, and a NAT 'masquerade' rule on the WAN so many private clients share one public IP.
NGFW concepts and multi-vendor translation
Next-gen firewalls (FortiGate, Palo Alto) think in zones and policies: assign interfaces to zones, then write policies that allow/deny by source/destination zone, address, service and application, with NAT and logging. The lesson across all vendors: the intent is universal (an interface IP, a default route, a NAT rule, an allow/deny policy) - only the syntax changes.