Add: Load and Performance Test (#2054)

* Add: Load and Performance Test

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

* Update content/roadmaps/113-qa/content/104-qa-non-functional-testing/100-load-and-performance-testing/readme.md

Signed-off-by: NaveenKumar Namachivayam ⚡ <catch.nkn@gmail.com>
Co-authored-by: Kamran Ahmed <kamranahmed.se@gmail.com>

content/roadmaps/113-qa/content/104-qa-non-functional-testing/100-load-and-performance-testing/readme.md

@@ -1 +1,15 @@
-# Load and performance testing
+# Load and 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 to monitor and improve 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`. 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
+
+Load Testing is one type of performance testing. It helps to evaluate the application under tests' behaviors such as response time, throughput, pass/fail transactions, and more under the normal workload. e.g., cart checkout response time is 500 milliseconds under typical business hours.