What is the difference Between purchasing and selling?

What leverage is in the dealing centre and what is the difference between purchasing and selling prices on currency pairs?

When a trade is made in forex, it has two sides, someone is buying one currency in the pair, while another individual is selling the other. That is called purchasing and selling in Forex.

That's quite a nice and simple answer. You made it very simple for the traders to understand. Thanks for your response.

@mailto2muthu ...asking about difference in purchasing and selling price difference...
Is that supposed to mean "not literally difference of buy and sell" but gap,
eg. USD/INR is 64 sell and 66 buy, so difference is inr. 2 averagely.

Every currency price we see is always against some other currency
one currency is called base currency and other is quoted currency
like USD INR
USD is base currency and INR is quoted
(Currency pairs are sometimes then written by concatenating the ISO currency codes (ISO 4217) of the base currency and the counter currency, separating them with a slash character. Often the slash character is omitted, alternatively the slash may be replaced by ".", "-", " ", and etc. A widely traded currency pair is the relation of the euro against the US dollar, designated as EUR/USD. The quotation EUR/USD 1.2500 means that one euro is exchanged for 1.2500 US dollars. Here, EUR is the base currency and USD is the counter currency.)
.
the difference between two quotes that we see is the "spread" we see.
For physical currency dealer it is the price gap they keep to ensure profits
.
and online in trading exchanges it is just the bid ask spread between buyers and sellers.

If I understand you well, in the forex market currencies are traded in pairs. If you think the relative value of the euro will increase against the dollar, you can go long on a EURUSD trade.

Thank you all. Now I cleared about this.