Diffrence bitween joint venture and subsidiary

DEAR ALL ,

TWO PVT LTD CO. A AND B  ENTERED INTO JOINT VENTURE AGREEMENT. THEY HAVE FOUND AB PVT LTD IN WHICH CO A HOLDS 51% SHARE AND B HOLDS 49 % SHARES. SO PLS CLARIFY RELATION BETWEEN A & AB IS OF HOLDING SUBSIDIARY OR IS IT JOINT VENTURE.