What is malwarebytes tray application?

Malwarebytes is an anti-malware app. Malware are apps that try to scam you. If you installed the free version then for 14 days, it will continually scan your mac for malware that might be trying to come in. You would know that it is running because you see it in the tray application.

You should see the Malwarebytes icon by the date/time in the upper right corner of your MacBook device. You can right click to see options. You can also go into Malwarebytes settings to disable the tray as well.

You don't need any anti-virus/malware protection on your mac if it isn't too old?

Corporate/business versions, the appearance of the tray icon is controlled by the policy the endpoint is placed in. I can't post a screenshot, but edit a policy, find the "endpoint interface options", and currently the first toggle "Show Malwarebytes icon in the notification area". In many installations, in the All Programs,MalwareBytes Start menu, there's an item to elect displaying the icon. I'm not certain if that can override policy settings though. Edit: I read "where is . . . .". What is . . . . on Mac's I'm not sure, but PC's you can click, right-click, CTRL+click Etc. to bring up actions to take. For the business, server or cloud based version, the endpoint client is VERY sparce to nearly non-existent though, still. Malwarebytes is slowly working on enhancing the end user experience with a GUI hopefully to come.