Gravitational field can also be shown by lines of force. This is same in several ways as that of electric lines of forces. With one dissimilarity, electric charges are negative and positive which causes force of attraction among dislike charges and repulsion among like charges. While in phase of gravitation the force is always of attraction.
A line of force is drawn in such a way that at every point the direction of field is tangent to line that passes by the point. Thus tangent to any point on a line of force gives the direction of gravitational field at that position. Lines of forces are given in such a way that their density is proportional to the strength of field.