Add: Performance Testing (#2081)

Signed-off-by: NaveenKumar Namachivayam ⚡ <catch.nkn@gmail.com>

Signed-off-by: NaveenKumar Namachivayam ⚡ <catch.nkn@gmail.com>

content/roadmaps/113-qa/content/100-qa-basics/107-testing-techniques/101-non-functional-testing/performance-testing.md

@@ -1 +1,17 @@
-# Performance testing
+# Performance Testing
+
+Performance Testing is a subset of Performance Engineering. It is a process of evaluating a system’s behavior under various extreme conditions. The main intent of performance testing is monitoring and improving key performance indicators such as response time, throughput, memory, CPU utilization and more.
+
+There are three objectives (three S) of Performance testing to observe and evaluate: `Speed`, `Scalability` and `Stability`.
+
+## Types of Performance Testing
+
+Following are the commonly used performance testing types, but not limited to:
+
+- Load Testing
+- Stress Testing
+- Spike Testing
+- Endurance Testing
+- Volume Testing
+- Scalability Testing
+- Capacity Testing