An oil company makes a profit and funnels some of that profit into R&D, or building new drilling rigs, or exploring for new productive wells--if successful, their business will grow, more jobs will be provided, and more tax revenue collected. Because it is choosing to invest the money in the business, instead of taking it in profit, that money is tax exempt. Obama calls this private investment "corporate welfare".
The government funnels taxpayer money, in the form of grants and loans, into "green" businesses--which can't convince private lenders to invest their own money, and thus must rely on taxpayers and bureaucrats instead. Many of these businesses, coincidentally, I'm sure, are headed by major Democratic party donors, who take large salaries and kick back more donations. Many of these companies promptly go broke (proving the reluctant private investors correct in their assessments.)
Obama calls this corporate welfare "investment".
Note: Just to be clear...the word "is" appeared several times in the above paragraphs. "Is," a form of the verb "to be". In the first instance above, it is used with the past participle of the transitive verb "to choose" as a passive-voice auxiliary. In the second appearance, it should be taken to mean that the subject of the clause has the qualification or characterization specified in the antecedent.