Joined: 28 May 2003 Posts: 9 Location: NewJersey, USA
Transaction in CICS is a 4 character word/string that initiates the execution of a program. Task is one unit of work with in a transaction. Suppose like you start a program which interacts with use by a screen, as soon as you type in the transaction, program starts and diplays the initial screen and waits for user response. Until this part, it is one unit of work done by the transaction.
You can define CICS programs/Trasactions/etc by CECI DEFINE if you right authority. Or you can do even by a batch job submitted in TSO. Generally, these will be done by CICS Systems people on request and needs of a project/ company. Automatic Task Initiation is starting of a CICS transaction automatically based on some events like when a record is inserted in TDQ, a transactin gets kicked off automatically. You have specify these settings in DCT table.
Best book for beginers reference is CICS HANDBOOK by Yukihisa Kageyama, TATA McGRAW HILL Edition.