Newbie question - Trying to understand PROTECT_IN from guest setup

I have the following setup:
Internet on eth0
LAN on eth1 (192.168.1.0/24) - guest network
Wireless on eth2 (192.168.2.0/24) - private network

eth1 will connect to a wireless AP

While following guest network setup.

https://help.ubnt.com/hc/en-us/articles/218889067-EdgeMAX-How-to-Protect-a-Guest-Network-on-EdgeRouter

I just want to understand what this firewall rule mean still struggling with it.

For PROTECT_IN firewall

Under the step 4

4. Create Drop Rule
set firewall name PROTECT_IN rule 20 action drop
set firewall name PROTECT_IN rule 20 description "Drop LAN_NETWORKS"
set firewall name PROTECT_IN rule 20 destination group network-group LAN_NETWORKS
set firewall name PROTECT_IN rule 20 protocol all
commit

Does this mean that any IP cant access another IP on the networks I defined on "LAN_NETWORKS"? so it cant access other IPs on the same or different subnets. (when I say access like ping it)

I plan to use this on eth1 as this is my guest network.