How is PE so different from an old-fashioned conglomerate like GE, UTX, EMR or Lowe's Companies?     Each of these owns a portfolio of businesses outright.  The portfolios are actively managed: new businesses purchased, existing businesses sold,  R&D investments made to grow new product lines etc.?

Seems like the major distinction are: 1)The frequent use of debt (rather than equity capital) as a means of investing, and 2)pay out of the cash flows from the debt.

Course that seems to lead to other differences with the old-line conglomerates: 1)Highly leveraged companies, and 2)Lower credit ratings (implying higher risk of default); 3) Cash paid to debt-holders cannot be used to fund growth in the businesses.

What am I missing here? Would seem to me owning a selection of well-rated conglomerates would be a low-risk way of getting PE exposure...add in a small junk-bond allocation if you need an edgier investment.