According to the Codex Alimentarius real caviar comes from the roe of fish belonging to the Acipenseridae e Huso family, i.e. sturgeon.
The roe of other types of fish, or of other animals, or even artificial products made with other organic substances, although they are advertised with misleading names and sometimes explicitly called “caviar” are not caviar but substitutes (surrogates) or imitations, which cannot be remotely compared with the value, refined flavour and organoleptic properties of real caviar.
To know what you are buying it is extremely important to understand the label on the back of the packaging. The label observes the labelling instructions of the “Convention on International Trade in Endangered Species of Wild Fauna and Flora” (CITES), used throughout the world as obligatory for sturgeon roe. This is the only way the consumer can find out about the species of sturgeon that has produced the caviar involved, its origin, whether wild or farmed, the country of origin, the year of production, the producer and batch and, if applicable, its re-packaging.