The individual values that are on the chart itself are known as points or data points. A group of related values together make up a series.
A scatter plot would be best for non-related data points. A line graph would be best for related data points.
data series
data series
Data Series
legends
Data Series.
When it's related
The term you are looking for is "dataset." A dataset refers to a collection of data points or information that are organized and related to each other in a meaningful way.
data filter
When the data on the graph is continuous,it does make sense to connect the points on the graph of 2 related variables.
line graph rock