The only good reason to use VirtualBox (the Oracle VM manager they got from
Sun) is that it works on CPUs that lack "hardware virtualization" - what
Intel calls "VT-x" and AMD calls "AMD-x".

A surprising number of Intel CPUs lack hardware virt support.  AMD seems to
have shipped it on damned near anything with two or more cores, but a lot
of Intel "Pentium dual-core", "Core Duo" and even "Core 2 Duo" chips plus
the lower-power stuff (Nano) lacks it.

Which leaves you stuck with VirtualBox...

If you don't know what your chip supports, google it and you'll generally
find a tech specs page from Intel, AMD or whatever.  Look for VT-x, AMD-x
or the like if you've got something oddball.

Jim