Penetration Testing: in plain terms

TL;DR

Penetration testing is a controlled attack on a system performed by a security professional, to find what an unauthorised attacker could actually do. The output is a report that names every weakness reproducible by the tester, what each weakness could lead to, and what to change. The topics below cover the fundamentals: what a pentest is, how it differs from other security activities, the standard methodology stages, and what a useful report contains.

By Shubham Khandare, Delivery Manager, SecureLayer7Updated June 10, 2026

Topics

What is Penetration Testing?: plain-language definition, what it covers, why organisations run them.
Penetration Test vs Vulnerability Assessment: same words, different work. How they differ and when to use each.
Penetration Test vs Bug Bounty: paid researcher with fixed scope vs an open crowd. Coverage, cost, and contract differences.
Penetration Test vs Red Team: checklist coverage vs goal-led adversary simulation. When each fits.
Black Box vs Gray Box vs White Box: three ways to scope what the tester knows. Tradeoffs explained.
CREST vs CERT-In: two of the most-asked-for credentials. What each one means and when auditors require it.
Pentest Methodology Stages: reconnaissance, scanning, exploitation, post-exploitation, reporting. The five-stage model used by every serious team.
Pentest Report Formats: executive summary, technical findings, reproducible evidence, remediation. What a useful report contains.

References

[1]NIST SP 800-115 Technical Guide to Information Security Testing(NIST)
[2]PTES Penetration Testing Execution Standard(PTES)
[3]OSSTMM Open Source Security Testing Methodology Manual(ISECOM)

Related terms

Penetration testing, in plain terms.

What a pentest is, how it differs from a vulnerability scan or a red team, the methodology stages, and what a good report looks like. No prior security knowledge assumed.

Topics

References

Scope a penetration test.