I'm not a physicist (oops - i mean IANAP) so the standard dose of salt should apply but i have watched many lectures online about many topics within physics. My understanding is that it really is the same term but used a bit differently.

Einstein favoured a steady state term(iirc he used gamma for it) in the equations for GR which was called the cosmological constant. Along came hubble who discovered the expansion of the universe and Einstein finally gave up on the fudge-factor term he had inserted to keep the universe mostly static..

60 or so years go by until scientists in the mid 90's discover that the expansion of the universe is accelerating contrary to most of their expectations. They reinstate the fudge-factor term but this time to represent so-called dark energy and it's effects on space-time.

That pretty much brings it up to date. For more info find Susskind lectures on all kinds of physics on youtube and on the Stanford site with a few honourable mentions in the repository of the Perimeter Institute's public lectures available at their site.