Software designers sometimes need to present UML sequence diagrams like this one.
This kind of thing is absurdly fiddly to draw with most graphics packages. But there’s a language called PlantUML that allows us to write them as text and render them in various software tools, including WordPress with the plugin called PlantUML Renderer.
The text for this example is this:
@startuml skinparam monochrome true autonumber hide footbox actor User participant Browser participant Website database Database User->Browser: Select bookmark Browser->Website: Request page Website-->Database: Look up information Database-->Website: Return information Website->Browser: Return page Browser->Website: Request assets note over Browser, Website: Images, CSS, Javascript Website->Browser: Return assets Browser->Browser: Render page Browser->User: Read page User->User: Think @enduml