TCP/IP model layers?

[N64play]

I've been watching Chris Bryant's CCNA course on Udemey, and he talks about the TCP/IP model having 5 layers, with data link and physical matching the OSI model. Thing is, Netacads support material only mentions 4 layers. Seeing as Netacad is official Cisco material, I'm inclined to lean towards that, but how many layers should I be concerned with for the CCNA exam?

[Leonid Voronkin]

Consider 4 for exam

[Mark Malone]

yes i would stick with 4 for the exam as that was the original setup from DARPA model when it was originally created , i see a lot of posts these days with the physical layer included but originally it was not it was a 4 layer setup only

Application,Transport, Internet,Network