Airline ticketing and reservations involve two main steps:
a reservation temporarily holds a seat using a Passenger Name Record (PNR), while ticketing issues a paid electronic ticket (e-ticket) linked to that seat. You can compare and book flights online using portals like MakeMyTrip, Goibibo, or IRCTC Air. 
Key Systems
  • CRS (Computerized Reservation Systems): Used by individual airlines to manage their own seat inventory and flight schedules.
  • GDS (Global Distribution Systems): Large centralized networks like Amadeus and Sabre that link travel agents and platforms to multiple airlines.
  • PNR (Passenger Name Record): A unique 6-character booking reference code containing passenger details and itineraries. [1, 2, 3, 4]
The Booking Process
  • Search: Enter travel dates, passenger counts, and route cities.
  • Select: Choose preferred flight times, classes, and fares.
  • Verify: Input accurate passenger legal names and passport details if needed.
  • Pay: Complete transactions via UPI, credit/debit cards, or net banking to convert a held reservation into a confirmed e-ticket. 
If you'd like help with a specific trip, please share:
  • Your origin and destination
  • Estimated travel dates
  • Whether it is a domestic or international trip
I can guide you on the best booking windows and options!