The VC firm behind Facebook, LinkedIn, and Workday just raised $1 billion for its newest fund

When Greylock raised $1 billion for its 14th fund in 2014, the company said it was going to focus on two areas: enterprise cloud and mobile.

Two years later, the tech landscape has changed, and the legendary Silicon Valley VC firm has raised another $1 billion for its 15th fund to invest in the new future of emerging technologies.

"Some of these spaces are more mature now," Greylock partner James Slavet told Business Insider. "The $100 billion question is where are we going to find the next really really big companies. Are they going to look different in terms of the spaces we're in historically?"

Greylock's already had massive successes in its two core areas, consumer and enterprise. It's already invested in four public companies with $10-billion-plus market caps: Facebook, LinkedIn, Palo Alto Networks, and Workday. It has investments in another 80-plus companies spanning from social network Nextdoor to enterprise startups like Cloudera and Docker.

"Certainly a big part of what we're going to do is going to be consumer network businesses, which can be either marketplaces or social platform kinds of businesses," Slavet said. "On the enterprise side, we continue to do a lot of investments in security, cloud infrastructure and SAAS over the last couple of funds."

However, the firm also intends to look at emerging technologies like virtual reality, artificial intelligence, and machine learning, because that's where a new wave of billion-dollar businesses might be born, Slavet acknowledges.

"A lot of entrepreneurs are looking at what are the windows are opening up now, and it's very different than 15 years ago where you could get customers through Google Search or a couple years ago where you could get customers through the App Store. What's the new distribution?" Slavet said.

While it may be exploring new subject areas for the firm, Greylock is going to continue to remain rooted specifically in the US space, even when some rival firms, like Sequoia, are continuing to invest in international.

"it's hard ot be successful investing in a country if you're not in the country. We think it's hard to fly in and fly out and to be successful investing internationally," Slavet said. "Our focus in the US and consumer enterprise tech and helping those companies scale, focusing on that is the best way we can be successful in terms of driving returns."