Is there any relationship between interfaces and firewall?

[qadeer37]

Can we call firewall an interface?

 

[jmcilhinney]

An interface is a surface (physical or abstract) where two separate systems come together and interact. Depending on how you look at things, I guess you could consider a firewall an interface but, more reasonably, a firewall is a system and it has two interfaces: one facing the outward and one facing inward.