The social web interactions have extended the sharing and the growth of web resources on the web. The collaborative web services (folksonomies) enable users to assign their freely chosen keywords (tags) to describe web resources. The advent of folksonomy has evolved the role of web users from consumers to contributors of information. Thus, users attribute their descriptive tags to annotate, organize and classify web resources of interests. Folksonomy became popular with the emergence of collaborative tagging. It offers a practical classification of web resources via the attributed tags. Nonetheless, the freely chosen tags weaken the semantic description of web resources. Folksonomy can give rise to a poor classification system based on ambiguous and inconsistent tags. Therefore, it is essential to pertinently describe the semantic of web resources to enhance their classification, findability and discoverability. The proposed approach represents a combined semantic enrichment strategy that explores collaborative tagging towards describing each web resource using different types of descriptive metadata, namely relevant folksonomy tags, content-based main keywords and matching ontology terms. The experimental evaluation has shown relevant results attesting the efficiency of our proposal. The alignment of social tagging with the ontology will not only enhances the classification of web resources but also constructs their semantic clustering. This emergent semantic will establish new challenges to improve the context-aware recommender systems of web resources in different real-world applications (healthcare, social education and cultural heritage).