StreamPlot

StreamPlot[{vx,vy},{x,xmin,xmax},{y,ymin,ymax}] generates a stream plot of the vector field {vx,vy} as a function of x and y. 

StreamPlot[{{vx,vy},{wx,wy},…},{x,xmin,xmax},{y,ymin,ymax}] generates plots of several vector fields. 

StreamPlot[…,{x,y}∈reg] takes the variables {x,y} to be in the geometric region reg. 

Please visit the official Wolfram Language Reference for more details and examples on core symbols.