Not exactly. In physics, a force field is a way to picture the effects that electric charges have on one another. Instead of talking about the force a positive (+) charge exerts on an electron, we can say the charge creates a force "field" in the empty space around it. An electron put down at any place in this force field is pulled towards the + charge; a positive charge set down at the same place is pushed away.
Try putting down "test" electrons with the mouse to see which way the
field points and how strong it is; the line points in the direction in
which the electron will move, and the length of the line tells you the
strength of the force at its current location. You can drag the mouse,
or you can press the "R" key to have your computer put down electrons.
OK, I get what a force field is (although it's a stretch to think of a
force field as a property of empty space). What is a "line of force"?
You can visualize "lines" of force by looking at the forces created by
the field in many different places; imagine connecting the lines from
all the electrons you have placed. Press "L," and the computer will
show you the pattern formed by all these connected lines. The lines in
this pattern are known as "lines of force." Force field lines "coming
out of" the big + charge "go into" the big - charge, so those two
charges are "connected" by field lines.