Pro might indicate high speed, but it will depend upon the manufacturer of the card.

The word Pro is used on quite a few cards.
It does not necessarily mean anything.

Here is a link to a chart for cards used on the Canon Rebel 300D.

http://www.robgalbraith.com/bins/multi_page.asp?cid=6007-6425

The closer to the top of the list, the faster the card when used on the Canon Rebel.

Note: many Pro cards are far down on the list.

A fast card seldom makes any difference on the average digital camera. But it does make a difference on DSLR (Digital Single Lens Reflex) cameras.

If a fast card is required or suggested for a particular camera, that information will be in the User's Manual.

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