Manual Testing is a process of finding out the defects or bugs in a software program. In this method the tester plays an important role of end user and verifies that all the features of the application are working correctly.
The tester manually executes test cases without using any automation tools. The tester prepares a test plan document which describes the detailed and systematic approach to testing of software applications. Test cases are planned to cover almost 100% of the software application. As manual testing involves complete test cases it is a time consuming test.
Manual Testing is performed by a human sitting in front of a computer carefully executing the test steps.
Automation Testing means using an automation tool to execute your test case suite.The automation software can also enter test data into the System Under Test , compare expected and actual results and generate detailed test reports.Test Automation demands considerable investments of money and resources.
It involves the testing of database triggers and logical views which are going to support databaserefactoring. It performs module testing of databasefunctions, triggers, views, SQL queries etc. It validatesdatabase tables, data models, database schema etc. It checks rules of Referential integrity.
API testing is a type of software testing that involvestesting application programming interfaces (APIs) directly and as part of integration testing to determine if they meet expectations for functionality, reliability, performance, and security. Since APIs lack a GUI,API testing is performed at the message layer.