Many people who studied Spanish in high school remember having a Spanish dictionary as part of the required books. Like all things this has now improved. Today anyone can translate back and forth from English to Spanish.
One Spanish dictionary is hosted by Google. It includes over a dozen languages. One of them is Spanish. It translates any length of text. These translations aren’t exact, but they’re pretty good.
Babelfish and later Alta Vista provided the first translator on the Web. A Spanish dictionary was included. It can translate many languages to and from Spanish. One issue this site has is that translations brought back to the original language have changed. Some people found this a useful feature. It could be used to generate alternate versions of sentences or paragraphs. But it also seemed to mean that the translations weren’t very accurate.
The Spanish dictionary found at Google isn’t like this. If a phrase is translated from English to Spanish and then back from that Spanish to English it’s usually identical to the original phrase. This is better for the purpose of translation even though the re-write capability isn’t present.
There is another Spanish dictionary that isn’t a translator. Oxford’s Spanish dictionary translates, but also offers pronunciation keys and definitions of English and Spanish words. One word to try is water. Agua is the Spanish word. It’s a feminine noun but becomes masculine when it’s singular. The Oxford entry continues by showing many different forms for the Spanish word for water. It’s very detailed.
Looking up mother in the Spanish dictionary brings us the Spanish madre. It also brings up a transitive verb version mimar. Transitive is like the word used in the sentence: she mothers me. Langua materna is Spanish for mother tongue.
Jacket can be found in the Spanish dictionary. If worn it’s chaqueta. But the jacket covering a book is sobrecubierta.
It seems that when it comes to a Spanish dictionary, Oxford’s is the best and most useful.