Let me help ease your confusion, @Jen421.

When you select the Save and Close button, it will save the transaction you're creating and close the page. However, the Save and Send button will let you save the transaction and send or email it directly to your recipient.  

You can click the drop-down arrow so you'd be able to see the different options to save and close your transactions. 

I've added these articles as an additional reference on how you record your business-related transactions in QuickBooks:

• What is the difference between an invoice, sales receipt, bill, and statement?
• What is the difference between bills, checks, and expenses?
• Customize invoices, estimates, and sales receipts in QuickBooks Online

Always feel free to leave a comment below if you have other questions about tracking income and expense transactions in QuickBooks.