Elliptic Curve Digital Signature Algorithm or ECDSA is a cryptographic scheme for producing digital signatures using public and private keys.
An attack targets particular nodes in a network by surrounding them and obscuring their view of the entire network. The attacker is then able to feed the targeted node false or no information.
The Bitcoin Protocol uses several different encoding schemes to represent data to users. The encoding schemes are chosen based on the data type, in order to optimise for human readability and conserve disk space.
An exchange is an institution which acts as a market-maker between parties who wish to buy and those who wish to sell. Exchanges simply facilitate trades between parties for a fee.