Abstract: A server for generating trained classification model for classifying an entity or classifying the similarity of the entity to other entities. The server comprises storage means arranged to store characteristics of a first plurality of entities, wherein each one of the first plurality of entities is classified with a first classification. The server comprises a training module arranged to train a classification model to classify an input entity with the first classification, or to classify the similarity of the input entity to the first plurality of entities, based on characteristics of the input entity. The classification model is trained using characteristics of the first plurality of entities as training data. The server further comprises a transmitter arranged to transmit the trained classification model to a client device for use at the client device.