网络本体语言 (英文：Web Ontology Language，OWL) 旨在提供一种可用于描述网络文档和应用之中所固有的那些类及其之间关系的语言。OWL网络本体语言当前已经获得万维网联盟认可的，用于编纂本体的知识表达语言家族。 其功能在于为网络文档和应用中固有的类以及其间的逻辑关系提供描述，使得基于此技术的网络应用更加 人性化和智能化，节省用户自身资源搜索时间并将这些处理交给计算机系统内部处理。基于不同的语义论特性 此家族语言大致分为两个系统： 基于描述逻辑进而丰富表达和精准计算属性的OWL DL和OWL Lite，以及以资源描述架构（英文：resource description framwork:RDF） 提供兼容叙述的OWL Full。 网络本体语言已经被认为是语义网技术的基础语言并吸引了包括学术和商业范围内人士的广泛兴趣。

The Web Ontology Language (OWL) is a family of knowledge representation languages for authoring ontologies. Ontologies are a formal way to describe taxonomies and classification networks, essentially defining the structure of knowledge for various domains: the nouns representing classes of objects and the verbs representing relations between the objects. Ontologies resemble class hierarchies in object-oriented programming but there are several critical differences. Class hierarchies are meant to represent structures used in source code that evolve fairly slowly (typically monthly revisions) whereas ontologies are meant to represent information on the Internet and are expected to be evolving almost constantly. Similarly, ontologies are typically far more flexible as they are meant to represent information on the Internet coming from all sorts of heterogeneous data sources. Class hierarchies on the other hand are meant to be fairly static and rely on far less diverse and more structured sources of data such as corporate databases.