What can one expect from molecular dynamics simulations of lipid systems, given the general possibilities and limitations of molecular dynamics described in the previous section? Obviously, it is important to know at which time and length scale the processes occur. A brief overview is given here, and a more elaborate account can be found in. Apart from the fundamental considerations of time and length scale that have to be taken into account when planning a simulation, there are a number of technical choices to be made. The most important technical choices are treated briefly below.