C4: System Context
A C4 System Context diagram: a person, an internal system in an enterprise boundary, and an external system, joined by labelled relationships.
c4-system-context.mmd
C4Context
title System Context for Internet Banking
Person(customer, "Personal Banking Customer", "A customer of the bank")
Enterprise_Boundary(b0, "Bank") {
System(banking, "Internet Banking System", "Lets customers view accounts")
SystemDb(ledger, "Ledger", "Stores transactions")
}
System_Ext(mail, "E-mail System", "Sends e-mails")
Rel(customer, banking, "Uses", "HTTPS")
Rel(banking, ledger, "Reads from and writes to")
Rel_Back(customer, mail, "Sends e-mails to")
Rel(banking, mail, "Sends e-mail using")