Growth investors are always on the lookout for ways to tap into the most exciting and fast-growing sectors of the economy.

Fortunately, the Australian share market offers several exchange-traded funds (ETFs) that provide exposure to some of the biggest global megatrends with just a click of the button.

If you're looking for ASX ETFs that could deliver strong returns over the long term, then these three funds might be worth considering. Here's what you need to know about them:

BetaShares Cloud Computing ETF (ASX: CLDD)

One of the most promising areas of technology could be cloud computing, and the BetaShares Cloud Computing ETF gives investors a simple way to gain exposure to this rapidly expanding sector.

This ASX ETF provides investors with easy access to a portfolio of global cloud computing leaders. This includes companies that develop, operate, or provide cloud-based infrastructure and services.

The shift towards cloud-based solutions continues to accelerate as businesses and consumers increasingly rely on cloud platforms for data storage, cybersecurity, artificial intelligence, and remote working solutions.

Among its holdings are the likes of Twilio Inc (NYSE: TWLO) and Snowflake Inc (NYSE: SNOW). Betashares recently tipped CLDD as a buy.

BetaShares S&P/ASX Australian Technology ETF (ASX: ATEC)

For investors looking for homegrown tech opportunities, the BetaShares S&P/ASX Australian Technology ETF could be a great option. This ETF offers exposure to the top-performing technology companies listed on the ASX, including market leaders in software, digital payments, and e-commerce.

Some of the ETF's key holdings include Afterpay parent company Block Inc (ASX: XYZ), Xero Ltd (ASX: XRO), and WiseTech Global Ltd (ASX: WTC). These companies have carved out strong competitive advantages in their respective industries and have significant growth potential both locally and internationally.

With Australia's tech sector continuing to expand and mature, ATEC provides an easy way to gain diversified exposure to this high-growth segment without the need to pick individual stocks. If the Aussie tech sector continues its upward trajectory, this ETF could generate solid returns for long-term investors. It was also recently named as a buy by the team at Betashares.

BetaShares Global Cybersecurity ETF (ASX: HACK)

Finally, cybersecurity is becoming an increasingly critical industry, with businesses and governments around the world ramping up their investments to protect against rising cyber threats. The BetaShares Global Cybersecurity ETF allows investors to tap into this growth theme by providing exposure to some of the world's leading cybersecurity companies.

The ASX ETF includes major players such as CrowdStrike (NASDAQ: CRWD), Palo Alto Networks (NASDAQ: PANW), and Fortinet (NASDAQ: FTNT)—companies that are at the forefront of defending against cyberattacks, data breaches, and digital espionage. With global cybercrime expected to cost trillions of dollars in the coming years, businesses and governments have no choice but to increase their cybersecurity spending.

Given the essential nature of cybersecurity services in the digital age, this ETF has the potential to deliver strong long-term returns as the industry continues to expand.