In an attempt to salvage my (sadly) previously incorrect answer, and to add to anttix's superlative answer, here is a quote from Stepper cable for MKS Boards pinout, which clearly shows the difference - locking and non-locking, and pitch difference (note the thickness of the plastic between each individual pin socket) - in the two plugs:

This pinout information will help you to use our 1 meter stepper cables correctly. Cable was made to be compatible with 6-pin JST connectors on NEMA 17 stepper on one side and 4-pin JST connector on other side. These cables are compatible with MKS BASE and MKS Gen boards that we sell in our store.

For compatibility with Anet board you will need to swap 2 wires - RED and BLUE on the 4 pin board side connector.

Whilst they aren't labeled PH and XH, it is pretty safe to assume that:

• For the control board, the 4 pin female connector on the left is the XH, and;
• For the stepper motor, the 6 pin female connector on the right is PH.

The mattmillan.com link in anttix's answer, whilst informative, unfortunately doesn't show both sides of the 4 or 6 pin connector.

Maybe It is most likely not... JST XH 2.54 6 pin female

and the reverse side, showing the locking, with the male PCB connector

In an attempt to salvage my (sadly) previously incorrect answer (at the bottom), and to add to anttix's superlative answer, here is a quote from Stepper cable for MKS Boards pinout, which clearly shows the difference - locking and non-locking, and pitch difference (note the thickness of the plastic between each individual pin socket) - in the two plugs:

This pinout information will help you to use our 1 meter stepper cables correctly. Cable was made to be compatible with 6-pin JST connectors on NEMA 17 stepper on one side and 4-pin JST connector on other side. These cables are compatible with MKS BASE and MKS Gen boards that we sell in our store.

For compatibility with Anet board you will need to swap 2 wires - RED and BLUE on the 4 pin board side connector.

Whilst they aren't labeled PH and XH, it is pretty safe to assume that:

• For the control board, the 4 pin female connector on the left is the XH, and;
• For the stepper motor, the 6 pin female connector on the right is PH.

The mattmillan.com link in anttix's answer, whilst informative, unfortunately doesn't show both sides of the 4 or 6 pin connector.

For the sake of completeness, but at the risk of going off-topic, the connector to the printer controller board is often a DuPont, and not a JST, particularly in, but not limited to, Arduino (Atmel/AVR based) boards.

From the same website, this page Stepper cable for RAMPS pinout, shows the DuPont connector to the control board and the JST-PH-6P connector to the stepper motor (I've not fixed the typos in the quoted text):

This pinout information will help you to use our 1 meter stepper cables correctly. Cable was made to be compatible with 6-pin JST connectors on NEMA 17 stepper on one side and RAMPS board connector (also called dupont connector) on other side. Main feature of RAMPS stepper header and this cable is that you can reverse stepper direction by turning connector on RAMPS 180 degree.

This cable is aslo compatible with CNC V3 shields for Arduino UNO and other electronic boards for 3D Printers and CNC control. Please observe the following piut diagram to make sure that your particular electronic board is compatible.

Note: I'm not promoting this particular website, it just so happens that they have the best comparison photos.

Maybe It is most likely not... JST XH 2.54 6 pin female

and the reverse side, showing the locking, with the male PCB connector

Maybe... JST XH 2.54 6 pin female

and the reverse side, showing the locking, with the male PCB connector

In an attempt to salvage my (sadly) previously incorrect answer, and to add to anttix's superlative answer, here is a quote from Stepper cable for MKS Boards pinout, which clearly shows the difference - locking and non-locking, and pitch difference (note the thickness of the plastic between each individual pin socket) - in the two plugs:

This pinout information will help you to use our 1 meter stepper cables correctly. Cable was made to be compatible with 6-pin JST connectors on NEMA 17 stepper on one side and 4-pin JST connector on other side. These cables are compatible with MKS BASE and MKS Gen boards that we sell in our store.

For compatibility with Anet board you will need to swap 2 wires - RED and BLUE on the 4 pin board side connector.

Whilst they aren't labeled PH and XH, it is pretty safe to assume that:

• For the control board, the 4 pin female connector on the left is the XH, and;
• For the stepper motor, the 6 pin female connector on the right is PH.

The mattmillan.com link in anttix's answer, whilst informative, unfortunately doesn't show both sides of the 4 or 6 pin connector.

Maybe It is most likely not... JST XH 2.54 6 pin female

and the reverse side, showing the locking, with the male PCB connector