Portfolios are defined by the split between defensive and growth assets. An investor living off the income from a portfolio will favour defensive assets (or "income assets") whereas some young dude who watched Wall Street yesterday on Netflix will go for growth assets.

It's not as simple as that, of course. Most investments have both growth and income characteristics. Many investments selected for their yield can experience price volatility (shares in Telstra or the banks, for example); and a risky growth asset can surprise you by kicking off a decent dividend (as some of the mining services companies did).