Testing can be mainly classified into manual and automated testing. With regard to this certain questions come to mind.
They include:
What is the basic difference between the two types of testing?
What are the elements of challenges involved in both manual and automated testing?
What are the different skill sets required by a software tester for manual and automated testing respectively?
What are the different job prospects and growth opportunities among software testers who do manual testing automated testing respectively?
Is manual testing under rated to automated testing in anyway(s)? If yes, how?
How differently are the manual testers treated in comparison to automated testers in the corporate world? (If they truly are differentiated in any terms as such)
Automated testing is any type of testing where you are using one piece of code / program to test another piece of code / program. This can be unit testing as described above, or it can be via a specific automation tool, such as TestComplete, QTP, Selenium, etc.. Unit tests tend to be created and executed by the developer of the code in question, whereas GUI automation will more probably be carried out by a software QA specialist. Certain types of testing, such as performance and regression testing, are well suited to automation, whereas others, such as usability testing, are not.
Manual testing is a process where a person directly tests a piece of software, often by carrying out the type of actions and end user might carry out. Many professional testers, such as those involved in exploratory testing, would suggest that you while unit testing is cost effective, manual testing is similarly important and cost effective.
For some wonderful insight into the pitfalls of automated testing, you should read Linda Wilkinsons recent blog. Other good resources to read include discussions from the software testing club, and the automated testing part of SQAForums.
If you haven't already done so, SQAforums is well worth joining to ask any questions relating to what's involved in testing, as well as for job prospects.