What does courier mean?

[Tuan]

Dear all.
I've read/listened following conversation but I have not understood the word 'courier'.
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Credit card can be used in millions of locations worldwide. They can be used for buying things by telephone. This is useful if you want to buy things from another country. Listen to the conversation and complete the credit card slip above.

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Mindy: MacGizmos. This is Mindy speaking. How can I help you?
Caller: Hi. I'd like to order some software, please.
Mindy: Do you have a catalog number?
Caller: Yes, I do. It's GKX 371 243.
Mindy: Please hold... that's the “Death Star Defender” game on CD-ROM for Macintosh?
Caller: That's right.
Mindy: What city?
Caller: I'm calling from London, in Britain.
Mindy: May I have your name and address?
Caller: Yes. It's Simon Alton, that's A-L-T-O-N, 42 Gladstone Terrace, London, W6 8BN, England.
Mindy: Simon Alton, 42 Gladstone Terrace, London, W6 8BN, England? And how do you want that sent, Simon? Surface, air, or courier?
Caller: Courier.
Mindy: That will be a total of $89.30, including delivery.
Caller: Fine.
Mindy: And how are you paying?
Caller: MasterCard®.
Mindy: May I have your number?
Caller: 5055 6631 8901 4247.
Mindy: 5055 6631 8901 4247. And the expiration date on the card?
Caller: September next year.
Mindy: And what is the name actually printed on the card?
Caller: Simon W. Alton.
Mindy: That's great, Simon. Your CD-ROM will be there in a few days. Thank you for calling MacGizmos.
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Although I checked dictionary but I couldn't find the meaning of courier which is suitable for this context.
I only found 'surface mail' = post that is sent by road, railway, or sea
If someone knows please give me an explanation.
I'm expecting for your reply.
Your sincerely

[Joe]

The word "courier" is based on the Latin word currere (= "to run").

One early meaning of courier was: a person who ran with a message (to deliver it fast - long before the days of telephone, cars etc).

Today, courier usually means:
- a person who transports and delivers documents and goods
- a company that transports and delivers documents and goods

Couriers are normally different from ordinary mail services because they may be faster, more secure, obtain a signature etc.

A good example of a company as a courier would be FedEx.