Dutch is famous for compound words — combining two or more words to create new meanings. The compound word is written as one word (unlike English, which often uses spaces or hyphens): slaapkamer (sleep + room = bedroom), voetbal (foot + ball = football), schooltas (school + bag = schoolbag), ziekenhuis (sick + house = hospital), vliegtuig (fly + thing = airplane), straatnaambord (street + name + sign = street name sign).
The logic of Dutch compounds is almost always transparent once you know the components: regenboog (rain + bow = rainbow), melkchocolade (milk + chocolate), huisdeur (house + door = front door), opblaasbootje (inflate + boat + diminutive = inflatable dinghy). This word-building system is a significant advantage for Dutch learners: once you have a reasonable vocabulary base, you can decode unfamiliar compound words by analyzing their parts.
Occasionally a linking element -s- or -en- appears between components: bedrijfsauto (company car), staatsgrenzen (state borders), bloemenmarkt (flower market). These linking forms are historical and follow patterns — generally, -s- appears when the first element is a noun ending in a specific way. While the rules are not simple enough to summarize briefly, exposure to Dutch text quickly builds an intuitive feel for which form sounds right.