All markings on roadways can be grouped into "Pavement Markings" That includes lines, pavement messages and bike lane markings.
Any line that runs parallel with the roadway would be considered a Longitudinal Pavement Marking.   These include but are not limited to; 6" Solid White, 6" Double Yellow and 6" Skips.  The skips lines can be yellow or white and at different intervals. For  example, the most common skips would be either a  6" Yellow  10'-30' Skip or a White 6" 10'-30' Skip. 10' being the actual colored stripe and 30' being the unstriped interval.   If the line you are talking about separates opposing traffic, it would most likey be either a 6" Double Yellow or a 6" Yellow 10'-30' Skip.  If the line you are talking about separates traffic that flows in the same direction it would be either a 6" Solid White or a 6" White 10'-30' Skip and both of these could be considered Lane Lines.  
As stated in the MUTCD ( The Manual on Uniform Traffic Control Devices )
The general functions of longitudinal lines are:
A. A double line indicates maximum or special restrictions,
B. A solid line discourages or prohibits crossing (depending on the specific application),
C. A broken line indicates a permissive condition, and
D. A dotted line provides guidance.
MUTCD ( Manual on Unifrom Traffic Control Devices )