Outlook vs. Exchange
Microsoft Exchange handles your emails. Rather, it handles them behind-the-scenes: you generally don’t have to get into Exchange to get your emails, just Outlook. Outlook is your mail client, the thing you use to send mail and look at the mail you’ve received, while Exchange is your mail server, which manages the resources needed to get the mail to you in the first place.
Since it’s a business feature and not a consumer one, the odds are you won’t be interacting with it very often (we do because we administrate business mail accounts!). Exchange also handles things like sharing or un-sharing mailboxes, as well as backing up your emails.
OneDrive vs. SharePoint
SharePoint is like Exchange, but for OneDrive, Teams, and a handful of other products! One large difference though is that SharePoint is designed to be a usable library as well as an archive. SharePoint allows you to design ‘sites’, (which are more like collections of files instead of websites) that can store and share files in the same way Google’s suite of services does, meaning team members who have access can modify the host file in real time. That way, you don’t have to merge files! If you’re worried about someone getting access to files they shouldn’t, SharePoint allows you to add and remove people on an individual basis. Additionally, most Microsoft products keep a log of changes made, although it doesn’t go back forever.
Where OneDrive only backs up files for one person, and those files aren’t available unless shared, SharePoint handles the backing up and the sharing at the same time.