MRR stands for Monthly Recurring Revenue — the predictable, repeating revenue a subscription business earns each month. Unlike one-off sales, it is the same money that comes back every billing cycle, which is why it is the core metric in SaaS. MRR is typically broken into new MRR, expansion MRR, and lost MRR from churn, and the sum is what the business actually plans around.
In plain English
MRR is the subscription paycheck. One-time deals are nice, but MRR is the base that keeps the lights on. When a SaaS company says it grew, it usually means its MRR went up — and whether that growth is real depends on how much came from churn and expansion.
Why it matters to you
If you sell a subscription, your commission and quota are often tied to MRR, and your forecast is an MRR number, not a dollar-of-anything number. And since MRR compounds month over month, even a small, steady addition becomes a large base over time. Speaking fluent MRR — and knowing the difference between it and ARR — makes you look credible in any tech-sales interview.