1. A system for creating a response to a search query using product-related data, comprising: at least one memory which stores a product database and a hierarchic product model arranging a plurality of product categories in a hierarchy, said hierarchic product model defines a plurality of attributes for each one of said plurality of product categories and a plurality of values for each of said plurality of attributes; at least one hardware processor executing a code for: receiving—natural language product information for each of a plurality of products from a product-related dataset of an e-commerce data source, said natural language product information defining product elements of a respective said product; for each of said plurality of products automatically indexing one of a plurality of modeled product representations into said product database according to said hierarchic product model, said indexing is performed by: selecting model attributes from said plurality of attributes of said hierarchic product model, said selected attributes are corresponding to at least one of synonyms and similar terms of the product elements from a respective said natural language product information of the respective product; extracting from the hierarchic product model a plurality of hierarchic relations between the selected model attributes; and indexing a respective said modeled product representation of the respective product in said product database according to the selected model attributes and the plurality of hierarchic relations; modeling an input text defining a natural language search query by using said hierarchic product model to create a modeled search query; and automatically creating a response to said natural language search query by matching said modeled search query with some of said plurality of modeled product representations defined in said indexed product database.