What is the difference between an Pro and Standard account?

The primary difference between an Pro and Standard account lies in how trade execution costs are charged.

Pro Account: Spreads start from 0.0 pips, and a commission of $7 per lot (round trip) is charged.
Standard Account: There is no commission charge, but spreads start from 1.0 pips.

For example, if you were trading a standard lot of EURUSD:

Standard Account: With a spread of 1.0 pips, the spread cost would be $10 for executing the trade.
Pro Account: With a spread of 0.0 pips, the cost would be $7 in spread plus a $7 commission, totaling $7 for the trade.
 

The benefit of a Standard account is that there are no separate commission charges, as costs are included in the spread. On the other hand, the benefit of an Pro account is tighter spreads, which, even with the commission, generally result in lower overall trading costs.