What does "third leg of the stool" mean?
What is the meaning of this idiom?
At price points for a cluster that start below $45,000, a VxRail appliance is the third leg of the stool.
The whole citation explain quite well what are the other legs (emphasis mine) of the metaphoric stool. The offer from the vendor is composed of three main lines of product, two of them seeming more traditionnal and more usual than this "new" offering.
The last product is part of a range of products and makes the offer from the vendor complete and well-balanced...like the third leg of stool.
Between the Block family and VxRail lies VxRack, an architecture that scales linearly with the addition of up to more than one thousand nodes. VxRack uses a leaf-spine network architecture and implements ScaleIO or VMware Cloud Foundation for software-defined storage and deployment of a virtualized NSX network layer over the physical network.
At price points for a cluster that start below $45,000, a VxRail appliance is the third leg of the stool.
By the way,just in case this is the part that confuses you, the stool in question is that type (not the biological one)
Presumably it refers to one of several elements of a whole that together are necessary for it to do what it needs to do, just like a stool needs a third leg to stand up.
I'm guessing the text this sentence comes from is describing a system, talked about two other vital elements of it and is now getting to this one ?
"The third leg of the stool" relates to the reliance of a piece of furniture (a stool) on its three legs to support it. Each leg takes an equal amount of strain from the sitter and is, therefore, equally important and useful. The stool's legs are used as a metaphor that represent three aspects of an entity which are inter-reliant and dependent upon one another for the function of the larger entity.
"Quality merchandise" might be the "third leg of the stool" in developing a shoe business that already has "excellent customer service" and an "advanced stock administration system".