Every term a manual tester
must know in 2026.
60 terms in plain English, 1 to 3 sentences each, AI words included. This is the vocabulary of every manual testing interview. Read it till the words feel normal.
The basics
The words every interview starts with.
SDLC
The full journey of building software: plan, design, build, test, release. Testing is one stop on this journey.
STLC
The testing part of that journey, in order: understand requirements, plan, write test cases, run them, report bugs, close.
Test scenario
The one-line idea of what to check. "Check login works" is a scenario.
Test case
The detailed steps for one check: steps, test data, and the result you expect. One scenario becomes many test cases.
Test plan
The document that says what will be tested, by whom, when, on what devices, and what is out of scope.
Test data
The inputs you test with: accounts, cards, addresses. Always fake, never real customer data.
Test environment
The separate copy of the app where testers work, so real users never see your experiments.
RTM (traceability matrix)
A simple table proving every requirement has test cases, so nothing ships untested.
Entry and exit criteria
The conditions to start testing (build deployed, smoke passed) and to stop (cases run, no open critical bugs).
Verification vs validation
Verification asks "are we building it right?" (reviews, checks against design). Validation asks "did we build the right thing?" (actually testing the product).
Types of testing
Where most interview confusion lives. Get these four pairs right.
Smoke testing
A quick check that the build even starts and the main paths open. If smoke fails, you return the build without deeper testing.
Sanity testing
A narrow check on the one area that just changed, to see if it is sane enough for deeper testing.
Retesting
Checking the exact bug that was fixed, with the same steps and data, to confirm the fix.
Regression testing
Checking that a fix or new feature did not silently break something else around it.
Functional testing
Does the feature do what it should? Login logs in, search finds, payment pays.
Non-functional testing
How well it does it: speed, security, usability, behaviour on slow networks.
Black box vs white box
Black box: you test from the outside without seeing code, like a user. White box: you test with full view of the code. Manual testers live in black box.
Unit, integration, system
Unit tests one small piece of code, integration tests pieces talking to each other, system tests the whole app end to end.
UAT
User acceptance testing. Real users or the client try the software before release and say yes or no.
Alpha vs beta testing
Alpha: tested inside the company. Beta: tested by a small group of real outside users before full launch.
Ad hoc testing
Unplanned testing without documents, relying on experience. Useful, but exploratory testing is its disciplined cousin.
Exploratory testing
Testing without a script but with a goal: you learn the app and design your next check from what you just saw. Where the best bugs hide.
Test design techniques
How testers pick a few smart inputs out of infinite ones.
Boundary value analysis (BVA)
Bugs live at the edges. For a field accepting 18 to 60, you test 17, 18, 19, 59, 60, 61.
Equivalence partitioning (EP)
Group inputs that behave the same and test one from each group. For 18 to 60: one below, one inside, one above.
Decision table
When rules combine (valid/invalid username times valid/invalid password), write every combination as a row so no case is forgotten.
Error guessing
Experience-driven attacks: huge input, spaces only, emoji, double-tap on submit, internet off mid-payment.
Positive vs negative testing
Positive: it works with valid input. Negative: it fails politely with invalid input. You need both.
Test coverage
How much of the requirements your test cases actually touch. 100% of requirements covered does not mean bug-free, and seniors say so.
Bugs and reporting
The vocabulary of defects, and the classic severity vs priority trap.
Error vs defect vs failure
A human makes an error, which puts a defect in the code, which the user experiences as a failure.
Severity
How badly the bug hurts the product. App crash = high severity. The tester decides this.
Priority
How soon it must be fixed for the business. A spelling mistake on the payment page is low severity but high priority.
Defect life cycle
The states a bug travels: new, assigned, fixed, retest, closed. If the fix fails, it is reopened, not filed again.
Reproducible bug
A bug that happens again when the steps are followed. Your report must make it reproducible on the first try.
Deferred bug
A real bug the team agrees to fix later. Documented, prioritised, not forgotten.
Bug leakage
A bug your testing missed that a customer found in production. Teams track it to improve testing.
Hotfix
An urgent fix pushed straight to production for a serious live issue, tested quickly and narrowly.
Agile words
How work actually flows in most product teams today.
Sprint
A fixed work cycle, usually two weeks, ending with something demonstrable.
User story
A requirement written from the user's side: "As a user I can pay with UPI."
Acceptance criteria
The checkable conditions that make a story done. For a tester, these are half the test cases already written.
Definition of done
The team's agreed checklist for calling a story finished: coded, tested, bugs closed, criteria passed.
Stand-up
The short daily sync: what you did, what you will do, what is blocking you.
Backlog
The ordered list of everything the team may build, groomed regularly.
Retrospective
The end-of-sprint meeting about the process: what went well, what to fix next sprint.
Shift-left
Moving testing earlier: reviewing requirements and writing cases while the code is still being written, not after.
API and data words
The terms that make you stand out beyond the UI.
API
How the app talks to the server: it sends a request and gets a response, usually in JSON. Testers check APIs directly using Postman.
Status code
The three-digit result of an API call. 200 OK, 400 bad request, 404 not found, 500 server error.
401 vs 403
The favourite interview pair. 401: "who are you?" (not logged in). 403: "I know who you are, and no" (logged in, not allowed).
JSON
The text format APIs speak: names and values in curly braces. Readable with 10 minutes of practice.
GET vs POST
GET reads data, POST creates it. PUT updates a whole record, PATCH updates part of it, DELETE removes it.
SQL
The language for asking a database questions. A tester's use: check whether the bug is in the data or in the screen.
SELECT and WHERE
The two SQL words that cover most tester needs: SELECT picks columns, WHERE filters rows.
JOIN
Stitching two tables together on a shared column, like orders with the customers who placed them.
AI words for 2026
Interviewers now ask these. Examples use ChatGPT and Gemini.
AI (ChatGPT, Gemini)
Software that can read and write almost like a person. For a tester, a fast assistant that drafts test cases, edge cases and bug reports.
LLM
The brain behind ChatGPT and Gemini. It has read a huge amount of text, so it can answer and write for you.
Prompt
The instruction you type. "Write 5 test cases for a login page" is a prompt. Better prompts give better drafts.
Hallucination
When AI states something wrong but sounds fully confident. The reason a tester reviews every AI answer before using it.
AI-assisted testing
Using AI to draft test cases, generate test data and clean up bug reports, while you review and decide. The 2026 way of working.
Chatbot testing
Testing an AI feature where answers vary each time. You check for correct, safe and on-topic instead of an exact match.
Prompt injection
A trick where someone hides an instruction to make an AI misbehave, like "ignore your rules". A new security risk testers probe.
Data privacy with AI
The rule that keeps you safe at work: never paste real customer data into a public AI tool. Use fake data, always.
Recommended Udemy courses
Want a guided path through these topics? These are the courses I would point a manual tester to.
Learn Manual Software Testing + Agile with Jira Tool
Learn SQL + Security (Pen) Testing from Scratch
MasterClass Software Testing with Jira & Agile – Be a QA Lead
Software Manual Testing – Complete Course Beginner to Expert
The Complete 2026 Software Testing Bootcamp
Knowing the words is step one
Definitions get you into the conversation. Interviews are won by the answers behind them: how you explain severity vs priority with your own example, or walk through smoke vs sanity without stumbling. Learn the words here, then practise saying the answers out loud.
Want the answers, not just the words?
The 400+ Manual Testing Q&A kit turns every term on this page into the full interview answer: what to say, how to structure it, and the traps to avoid. AI questions included.