The assessment of digital competence should take into consideration different competence areas, as suggested by the Digcomp framework. The competences of each area have been established, but there are interrelationships between them which are still little studied. The application of structural equation modelling constitutes an interesting approach to study the association between the different variables studied, given the flexibility and the higher capacity of analysis, comprehension, and modelling of the relationships among different constructs that are involved in measuring digital competence. This study aims to propose a structural equation model, based on the interrelationship among the latent constructs of knowledge and digital abilities, namely information, communication, security, content creation, and problem-solving. In order to carry out the study, the ECODIES-v2 test, created for the assessment of the digital competence of compulsory students in Spain, was adapted and translated. It was applied to a sample of 810 students aged 11 to 19 years old, studying at schools in the district of Viana do Castelo, Portugal. The results show that there is a moderate/strong positive and significant correlation among the constructs, which fits into the theoretical structure underlying the model obtained.