Vocabulary is a complex intermediate component between oral and written language, which the influence on associated skills and general language abilities (e.g., decoding processing, comprehension) has been largely studied in children, suggesting its important role in literacy. The main aim of this article is to review some questions on vocabulary assessment and stimulation in children and identify the advantage of new technologies for evaluating and training vocabulary. It seems necessary to give the importance of vocabulary in language and literacy development, and the heterogeneity of vocabulary acquisition, depending on preschool word exposure (e.g., familial environment). After a state-of-the-art of conceptualization of vocabulary's notion, we revisit assumptions on vocabulary assessment and instruction indicating the main existing tools. This review lies in the attempt to enhance perspectives for new valid and effective tools using digital technologies.