String theory regards particles as (tiny) one-dimensional objects inspace-time -- paths or loops. String FIELD theory deals with functions defined on the space of all such strings. String field theory is multi-layered, often presented as involving topology, geometry, algebra and analysis, especially analysis in the sense of Riemann surfaces. The bottom layer is the topology of string configurations which in turn gives rise to "convolution" algebras of fields. The talk will provide interpretation of these algebraic structures from the point of view of operads. This focuses particularly on the subtleties of and fit naturally in to the existing framework in algebraic topology developed for studying spaces of the homotopy type of (iterated) loop spaces. The topological operads involved are moduli spaces for Riemann surfaces with marked points and decorations or compactifications as well as the more traditional ones for complex structures.