By "I've asked" I presume you asked FXCM? That explanation is very weird indeed.

Let me demonstrate, now that I've found some time to extract some real ticks (EUR/USD, Dukascopy feed):

Here's how ticks look:



First column is the time (including milliseconds) followed by bid & ask prices. When you get a tick you know that there has been at least one transaction with that bid/ask prices. There could have been more, but another tick is printed only if bid/ask prices changed since the last tick has printed.

If you look closely, all the above ticks are from the same minute 01:17 and I specifically looked for the very quiet period so that I can paste the full minute without forcing you to scroll too much. Trust me, during peak hours one minute more often than not sees more than hundred ticks. Tens of ticks can occasionally be printed inside one second.

Converting that tick data to 1min bars is quite straightforward, you detect the opening price (first bid: 1.37694 in the example above), closing price (last bid: 1.37714), highest price (1.37715), lowest price (1.37680) and you're done.

So you compress typically hundreds of ticks to just 4 numbers (losing lots of information in the process) to get a 1 min OHLC bar, but calling the resulting OHLC bar 'a tick' is insane.