Social Democracy: Neutered capitalism, large welfare state, some nationalized industries and regulations on capitalism. Some Social Democrats actually take a some what Marxian analysis of the economy.
Democratic Socialism: Democratic Government with a nationalized industry and full worker's ownership of the means of production usually with workers committees and co-ops. Typically Democratic Socialists differ from Marxist-Leninists on economic management, DemSocs argue for a Market Socialist economy, where Marxist-Leninists prefer a centrally planned economy. DemSocs differ from Marxist-Leninists on social policy as well, a Marxist Leninist would have you shot for disagreeing with the government, where as a DemSoc argues for socially liberal freedoms, even some (like myself) argue for legalization of drugs and prostitution.