Processes in Microsoft 365 for setting up Office apps, redeeming product keys, and activating licenses.
Windows Live Mail is free. Outlook is part of Office Home and Business and up, and hence not free.
Windows Live Mail offers e-mail capabilities and a calendar. Outlook offers these, plus tasks and notes.
Windows Live Mail does not have a programming interface. Outlook can be programmed using VBA code, both from within Outlook itself and from other applications.
Windows Live Mail doesn't work with Microsoft Exchange (corporate mail server). Outlook has full support for working with Microsoft Exchange.