Spanish and French are fusional languages; so are Sanskrit, Greek (classical and modern), Latin, Russian, German, Polish, Slovak and Czech. In fusional languages, segments of a word can convey multiple parts of the meaning. In the Latin word bon-us, the "us" tells us three things: that the gender is masculine, the case is singular, and the word is the subject of the sentence.
Most older languages, such as Turkic, Mongolic, Korean, Basque, Eskimo-Aleut and Finnish, are agglutinative. In an agglutinative language, each part of the word conveys only one part of the meaning. So a word with a very specific meaning can be very long, with each added syllable making the word more precise.
English is mostly fusional, with a few agglutinative holdouts: anti-dis-es-tab-lish-ment-ari-an-ism is a good example. It is hard to get a quick word in when your words are so long!