The soft infrastructure or social infrastructure[1]​ is made up of all the elements necessary to provide the services that maintain the economic, health, cultural and social standards of a population. The concept is contrasted with that of hard infrastructure (which is generally referred to simply by the word "infrastructure"), made up of constructions such as roads, bridges, railways, ports, airports, power lines, energy plants, etc.

Soft infrastructure includes both physical elements – for example specialized buildings and equipment – ​​and intangible elements such as communication, the rules and controls that govern the different systems, the financing of these systems or the training of their professionals.

Soft infrastructure is made up of institutions such as the financial system, the educational system, the healthcare system, the government system, the justice system, emergency services, the network of libraries, museums, sports centers and auditoriums, etc.

The essence of soft infrastructure is the provision of specialized services. Unlike the majority of the service sector, the provision of soft infrastructure services depends on highly developed systems and large specialized facilities, fleets of specialized vehicles or specific institutions.[2]​[3]​[4]​.

Several types of soft infrastructures can be described.