Market Capitalization is one way to rank the relative size of a cryptocurrency. It's calculated by multiplying the Priceby the Circulating Supply.
Market Cap = Price X Circulating Supply.
Circulating Supply is the best approximation of the number of coins that are circulating in the market and in the general public's hands.
Total Supply is the total amount of coins in existence right now (minus any coins that have been verifiably burned).
Max Supply is the best approximation of the maximum amount of coins that will ever exist in the lifetime of the cryptocurrency.
A Coin is a cryptocurrency that can operate independently.
A Token is a cryptocurrency that depends on another cryptocurrency as a platform to operate.
AltcoinPriceIndex reports on the trading activities of thousands of markets but does not directly sell any cryptocurrency. If you want to buy cryptocurrency, you can look at the Buy / Sell Section.
It's based on the current time. It's a rolling 24 hour period.