When investors think about real estate, the first thought is often real estate investment trusts, or REITs. That makes complete sense, and REITs are a key way to invest in the space. But if you're watching stocks in the real estate arena, in addition to industrial landlords such as Prologis (NYSE:PLD), you'll want to consider companies such as CBRE Group (NYSE:CBG) and disruptors such as Zillow Group (NASDAQ:Z).

The obvious place to look
When thinking about the industrial side of the real estate sector, one of the biggest names is Prologis. This REIT owns 670 million square feet of property in 21 countries around the world. It has 5,200 customers that span from retailers to third-party logistics companies. So Prologis is a massive company with huge exposure to global trade.

A not-so-exciting Prologis building. Source: Lukasz Poznan, via Wikimedia Commons.

Its focus is on distribution facilities located in key ports. This is not a "sexy" business. It is the nuts and bolts that get products from where they are made to where they are needed and sold.

In addition to owning properties, Prologis is also a property developer, building many of its facilities from the ground up. That approach, however, comes with risks. For example, during the 2007-2009 global recession, Prologis saw its results falter because it was building properties on "spec," or without a tenant ready to move in. That process exacerbated Prologis' already notable exposure to the fluctuations of international trade.

But if you're thinking about real estate and the industrial world, you should look at Prologis and similar REITs. That's especially true now that Prologis has begun to raise its dividend again after cutting it during the recession.

A different option
But not every real estate company is a REIT. And giant CBRE Group is one of the best examples. CBRE is a property manager, essentially running the day-to-day business of a building so the owner doesn't have to bother.

Like Prologis, CBRE's business spans the globe, with operations in 44 countries. It manages roughly 3.7 billion square feet of space. But CBRE is bigger than just that business. It also operates in financing, asset management, development, project management, and the valuation and advisory segments of the real estate market. And it's an important player in all of them.

Source: CBRE Group,, via Wikimedia Commons.

So while you can buy a REIT to get direct property exposure on an industrial level, you don't have to go that route. CBRE is a company that can give you direct exposure to the property markets in just as meaningful a way. And with CBRE's gigantic size, you'll get exposure to a broader swath of the institutional real estate market, too.

Disrupting the status quo
You might also want to look at the real estate space from a completely different direction, which is where Zillow offers an interesting and growing service. You probably know Zillow as a consumer-facing website and application. Perhaps you've even looked up a property using the service. But you aren't really the company's customer.

Zillow makes money by providing those looking to sell a property (i.e., real estate agents) with access to customers (i.e., property buyers). The buyers aren't paying; the agents are. In 2014 roughly 75% of the company's revenue came from real estate agents that use Zillow's suite of marketing and business technology tools to generate client leads and build their own brands and businesses.  

So Zillow is really serving its business customers by giving them access to you. And in the process it's disrupted the historical way in which the real estate market has run. It recently bought one of its biggest rivals, Trulia, cementing its position as a leader in the fast-changing online world, as it relates to real estate.

As the company continues to grow, look for it to keep expanding its reach in the real estate space. It will never be a Prologis or a CBRE, but it very well might wind up serving these customers or competing against them in some smaller ways. Indeed, Zillow already has its fingers in the mortgage space, so reaching further than just property listings is already in the cards.

That said, Zillow is a technology company, even though it works in the real estate space. So you'll need to watch both the property markets and technology developments if you invest here. The former will lead Zillow's top and bottom lines to fluctuate over time as the property cycle moves up and down. Fast-changing technology, meanwhile, could put the company out of business if it doesn't keep up with change. There's also the issue of valuation to keep in mind, since technology valuations can sometimes get stretched because of investor exuberance.

A different view of real estate
When looking at real estate, the easiest way to think about it is as property that's owned, such as the industrial properties that Prologis builds and runs. But there is so much more to the space. For example, not every company rents, which is why property companies such as CBRE are there to handle the day-to-day tasks, and so much more. And there's even technology at play, with industry leader Zillow helping to disrupt the normal flow of business in real estate. So if you're watching real estate, you should think outside the box (CBRE and Zillow) just as often as you think inside it (Prologis).

Reuben Brewer has no position in any stocks mentioned. The Motley Fool recommends Zillow Group,- Class C. The Motley Fool owns shares of Zillow Group,- Class C. Try any of our Foolish newsletter services free for 30 days. We Fools may not all hold the same opinions, but we all believe that considering a diverse range of insights makes us better investors. The Motley Fool has a disclosure policy.