Day2: Begin reading an automation related book and share something you've learnt by day 30

I'm reading Advanced Level Syllabus – Test Automation Engineer from ISTQB.
I've learnt something following:

Testware is necessary for the testing activities that include:
 Implementing automated test cases
 Monitoring and controlling the execution of automated tests
 Interpreting, reporting and logging the automated test results

Test automation has different approaches for interacting with a SUT:
 Testing through the public interfaces to classes, modules or libraries of the SUT (API testing)
 Testing through the user interface of the SUT (e.g., GUI testing or CLI testing)
 Testing through a service or protocol

Objectives of test automation include:
 Improving test efficiency
 Providing wider function coverage
 Reducing the total test cost
 Performing tests that manual testers cannot
 Shortening the test execution period
 Increasing the test frequency/reducing the time required for test cycles

Advantages of test automation include:
 More tests can be run per build
 The possibility to create tests that cannot be done manually (real-time, remote, parallel tests)
 Tests can be more complex
 Tests run faster
 Tests are less subject to operator error
 More effective and efficient use of testing resources
 Quicker feedback regarding software quality
 Improved system reliability (e.g., repeatability, consistency)
 Improved consistency of tests

Disadvantages of test automation include:
 Additional costs are involved
 Initial investment to setup TAS
 Requires additional technologies
 The team needs to have development and automation skills
 On-going TAS maintenance requirement
 Can distract from testing objectives, e.g., focusing on automating tests cases at the expense of executing tests
 Tests can become more complex
 Additional errors may be introduced by automation

Limitations of test automation include:
 Not all manual tests can be automated
 The automation can only check machine-interpretable results
 The automation can only check actual results that can be verified by an automated test oracle
 Not a replacement for exploratory testing