Can someone provide a detail difference between the terms custom application and custom app-id?

[jvalentine]

Custom application is an application running in your environment that was created by your organization (or specifically for your organization) and is not likely to be seen in other customers' environments.  

Custom App-ID is a custom signature that administrators can create on the firewall to control custom applications (or even common applications where an official App-ID is not yet available)

[TranceforLife]

Hi,

My understanding these terms are the same. You can create a custom application (additional app-id in Palo local database). 

EDIT: @jvalentine has better explanation 

[jvalentine]

@TranceforLife: I’m willing to bet the terms are also used interchangeably here in the community forums and potentially in the official documentation.

[BPry]

@jvalentine,

There's a lot of instances in the admin guides where a 'custome application' is really an app-id, I can't say I really recall the other way around being brought up though. 

[ice-quake]

 Once a custom app is defined will security policy implicitly block the custom app if it isn't referenced in any policy? 

[BPry]

@ice-quake,

Yes. For example if I make an app called 'WSL-Slate', I'll need a security policy that actually allows my users to access this 'WSL-Slate' application.