There were no computers of any sort in 1949 (when I was seven). No emails, no internet, and no cellphones. Phone calls from landlines were free in your local town, but expensive if you wanted to talk to someone in a different town, and very expensive indeed if you wanted to talk to someone in a different country. So, people used to send lots of letters instead.
You would write your letter on sheets of paper, like in the picture. There were no “biros” in those days, so you used what was called a “fountain pen”. It was called a “fountain” pen because it had a refillable reservoir (a very small tank) within the barrel of the pen, and “reservoir” is one of the meanings of the word “fountain”. (There, now you know!!!)
The ink we used in those days was a liquid, so you had to be very careful you didn’t smudge what you’d written before it dried. It was particularly hard for left‑handers (like me), because your writing hand tended to smudge the words as you wrote them.
When you’d finished your letter, you folded it, put it in an envelope, wrote the name and address of the person you were sending the letter to on the envelope, stuck a postage stamp on the envelope (which you could buy from the Post Office, which was a bit like a modern PostShop), and put the envelope into a letterbox (usually at the Post Office). Once or twice a day, postal workers would collect everyone’s letters from the letterboxes and send them on their way (by foot, bicycle, car, bus, train, or ship).
A letter might take several days to reach the person you wanted to contact (or weeks, if they lived overseas). So, if you needed to contact someone urgently, you would either phone them (which was expensive) or send a “telegram”. A telegram was a short message (similar to an SMS), but to send it you had to go down to the Post Office. You would write your message on a form and the Post Office clerk would send the message for you (by phone, or by using Morse Code).
Although telegrams were terribly expensive (they cost maybe a dollar or more per word, in today’s money), they were still cheaper than phoning, provided you only used a few words. The picture shows a typical very short message.