From socialist dictionary that used to be available on line:

Means of production. Land, factories, railways, offices, communications, etc. A mode (or system) of production is constituted by its forces and relations of production. The forces of production in capitalism include means of production and labour power. (See also FORCES OF PRODUCTION; RELATIONS OF PRODUCTION.)

Forces of production. What can be broadly understood as technology, the forces of production include materials, machinery, techniques and the work performed by human beings in the production of wealth. (See also HISTORY; RELATIONS OF PRODUCTION.)

Relations of production. Classes in society are determined by the possession or non-possession of the means of production. In capitalist society it is the relations of production which constitute the capitalist class and the working class. (See also CLASSES; FORCES OF PRODUCTION.)

Means of production are present in every society but only in the form of capital, according to Marx, when employed as a force of production.    Capitalist economics sees capital as wealth used to make wealth, regardless of whether it is a factory actually producing something or a large sum of money which is gambled to make more money, but actually that only redistributes wealth that has already been produced.