Hi Niwantha, The word "prevalent" is an adjective which means a common practice, condition or belief among a population at a particular time. Examples: 1. During medieval times, wife-selling was prevalent and acted as a way for a man to end an unsatisfactory marriage. (common practice) 2. Due to global warming, extreme weather patterns such as heat waves will become more prevalent in the future. / Obesity is increasingly prevalent in the United States and this will bring deadly consequences. (common condition) 3. Juche is a prevalent state ideology which is embraced in North Korea. (common belief) "Prevailing" is also an adjective (and its noun form is "prevail"). It expresses superiority, usually by means of power, number, status and so on. It also means to continue to exist despite some difficulty. "Prevailing" is used very often when describing the direction of trade winds. Examples: The prevailing political party is expected to face a tough election from opposition parties. The Ottoman Empire prevailed for more than 600 years and ended only in 1922. Prevailing southerly winds is the reason for an unusually mild winter this year. While there is some overlap in the meaning of both words, there are also some differences. I hope this helps.

to put simply prevalent=widespread. But also from prevailing/prevalent. prevailing= predominant, currently existing.superior. "the prevailing winds are from the south west" applies commonly to the coastal areas of south and south east England the direction of storms. And prevailing winds you may sometimes hear on a weather forecast. "the occurrence of alcohol abuse and drunkenness in English city centres, on Friday and Saturday nights, has become prevalent over the past ten years" <- using prevalent in the widespread sense. they have overlap and interchangeability except when using prevalent to mean WIDESPREAD