Zoho Books vs. Zoho Invoice vs. Zoho Expense Comparison
Zoho Invoice is a great free invoicing app. Zoho Books has all the features of Zoho Invoice plus a complete bookkeeping system that can track your company’s assets, liabilities, income and expenses. Meanwhile, Zoho Expense manages employee expense reports and reimbursements — a distinctly different purpose from either Zoho Invoice or Zoho Books.
Source : https://www.techrepublic.com/article/zoho-books-vs-invoice-vs-expense/