Money & Side Hustle Glossary: Terms Explained
Plain-language definitions of the 10 terms that come up most often in side hustle, freelance and investing advice
By the Monthly Income Booster editorial team · Updated · How we research and fact-check
On this topic
Most money jargon exists to compress an idea, not to exclude people — but a term you have not met before does exactly that until someone explains it. Each entry below defines the word, shows how the number behind it is actually worked out, and says what changes it. No entry is a dictionary paragraph: if a term has arithmetic underneath it, the arithmetic is on the page.
All terms
Every definition on the site, in alphabetical order.
- What Is a REIT? (Real Estate Investing for Beginners)
- What Is Affiliate Marketing? (Plain English)
- What Is Cash Flow? Definition and Examples
- What Is CPM? Cost Per Mille Explained for Creators
- What Is Dividend Yield? (Formula, Examples & Pitfalls)
- What Is FIRE? Financial Independence, Retire Early Explained
- What Is MRR? Monthly Recurring Revenue Explained
- What Is Passive Income? (Complete Beginner's Guide)
- What Is ROI? How to Calculate Return on Investment
- What Is RPM on YouTube? (And Why It Matters More Than CPM)
Where the terms get used
These words turn up throughout the calculators and guides, which is why they are defined rather than assumed. If a calculator asks for something you do not recognise, the definition is here and the calculator page states its assumptions too.
Official sources
Tax rules, limits and pay data change. Check the current figures with the primary source before acting on them.
Frequently Asked Questions
Why do these definitions include maths?+
Because most of these terms are a number with a name attached. Knowing that MRR stands for Monthly Recurring Revenue is much less useful than knowing that annual plans are divided by twelve and that churn sets the ceiling on how big it can get.
Is any of this financial advice?+
No. Everything here is educational. Consult a licensed professional before making a financial, tax or business decision.
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