Bitshares' core functionality is a p2p asset exchange for market-pegged assets, BTS being both shares in the organization and the currency over which the bitassets are synthesized and exchanged. for instance, our best products are bitUSD and bitCNY, but we also offer bitBTC, bitGOLD, and bitSILVER, as well as a variety of other less liquid products.
Understanding how the bitassets are created can be illustrative of the entire business model:
-someone wants to buy a digital version of USD, bitUSD. there are a variety of reasons someone might want this product: (1) it's digital and has all the beneficial characteristics of blockchain assets wrt transferability, fungibility, etc. (2) it earns an above average interest rate (currently ~5.6% for bitUSD), and (3) going long bitUSD is equivalent to going short BTS.
-someone wants a leveraged long bet on BTS, so they short bitUSD into existence and sell it to the buying party. this speculator offers an interest rate to attract buyers and has to put up collateral that automatically triggers a margin call if the price exceeds 300% of the shorted amount. The collateral is held in escrow on the blockchain and algorithmically released with either a margin call or covering the position. This process significantly reduces counterparty risk.
-Price feeds are used for each asset and updated frequently to manage the collateral system.
This is just one of the core functions of the Bitshares network, but it's what i consider the real innovation and value proposition of the system. i'm sure others can fill you in briefly on additional operations that could add value to the network.