Passenger Name Record (i.e. PNR), for Indian Railways, is a ten digit number identifying each reserved ticket.
This number is unique across e-ticket, i-ticket and over the counter tickets.
Each ticket has the name, age and sex of passengers, class of their travel, date of travel, journey start and destination,
reservation from and to (which can be different from journey from/to) and the train in which reservation is made.
During booking there is a status, which can change if the status isn't a confirmed berth/seat/coupe.
If it is a waitlisted (WL) or reservation against cancellation (RAC) ticket, the status would keep
changing when other bookings get cancelled or (rarely) when some emergency tickets get taken out of general pool.
How can I check PNR Status of Reservation?
PNR status can be checked vis SMS, Phone Call or Online.
PNR <10-digit pnr number> to 5676747 OR 54959 OR 139
IRPNR <10-digit pnr number> to 57886
Dial 139 and talk to operator.
There are several websites that provide PNR Status. The one you are on is one such, and as you would have noticed is
simple to use, mobile friendly, and maintains history of your PNR checks.
Where is my PNR?
In both printed and electronic tickets, PNR number would be displayed prominently on top row.
In case of electronic tickets you would get an SMS as well, containing the PNR.
Should I print the electronic ticket?
Not required. You can travel with the SMS received from IRCTC or show a soft copy of the ticket PDF
in your phone or laptop. Since SMS is accepted, that is the easiest mode of showing ticket.