With the advancements in bioinformatics and ecoinformatics tools, it has become feasible to utilize vast amounts of biodiversity information to describe biological patterns and attempt to assess the ecological and evolutionary processes underlying them, as well as to establish more effective and comprehensive conservation actions. However, existing information regarding biodiversity remains incomplete, with gaps, limitations, biases, deficits, and noise. In this regard, we acknowledge the need to discuss issues related to the use of large biodiversity databases and their quality, discussions that need to be conceptually structured. In this text, we will systematically describe the gaps, limitations, and biases in biodiversity knowledge, issues that are directly associated with the acquisition of species information in nature. Subsequently, we will outline the types of deficits and noise, which are problems associated with biodiversity databases. This is because the information present in primary records and large databases is frequently used inadequately. Additionally, we also point out perspectives on how to address these deficiencies in ecological/biogeographical work through appropriate database curation and the construction of maps of ignorance. Finally, we highlight future challenges, such as the need for new data collections, the training of new taxonomists, and the provision of financial support for the infrastructure and digitization of biological collections.