Recent advances on the understanding of

properties of nanocontacts involving metal atoms and

molecules are discussed. Different ways of generating

these nanocontacts are discussed, as well as different

theoretical approaches devoted to their study. Special

emphasis is made on the measurement and the

calculation of electrochemical properties. The reason

for this is that the electrochemical environment

appears as particularly suited for the design of

devices like nanoswitches and nanosensors. The most

generally accepted models and hypothesis are given,

but emphasis is also made on some items subject of

hot discussion in the field.