The use of the term “units” for college credit suggests that you may be in California.
If your previous college credit is all from community colleges, and you transferred to a California public university (UC or CSU), then the transfer credit is capped at 70 semester units (but all courses taken can be applied for subject credit). If your new university has a 140 semester unit limit, that means that you can take up to 70 semester units there without going over the limit.
For other situations, others may be able to help you better if you name the university.