Names for tool and variable elements are automatically assigned by ModelBuilder when you add or create the element. The assigned tool name is the same as the tool label.
Learn more about tool names and labels
Variable names are assigned according to the variable type. For data variables, the element name is the name of the dataset, and for value variables, the name is the same as the parameter name. If the element name already exists in the model, it is appended with a unique number.
You can change the name of any element (tools and variables) by right-clicking the element and clicking Rename.
Renaming is especially important for model parameters, since the name of the variable is what shows in the model's tool dialog. In the example below, the name of the variable is StudyArea.shp, which becomes the parameter name in the tool dialog, and you would probably want to rename the parameter variable to something meaningful for the user, such as Clip features.
The rules that ModelBuilder uses to name elements cannot take into account your intent or the numerous situational factors that make for clear, understandable element names. It's recommended that you rename elements to make the model easier to read and follow. While this is especially true for variable elements, you may find that renaming tool elements can add clarity to the model.
Almost all the models that you see in this documentation have had their variables renamed from the original names assigned by ModelBuilder.
- Changing the name of a variable does not affect the contents of the variable. For example, in the model below, the Bridges variable contains the value E:/Data/DocData/Example.gdb/Bridges. Renaming the variable Bridges to Tunnels does not change its value (for example, changing it to E:/Data/DocData/Example.gdb/Tunnels).
- Renaming a variable does not update the name of another variable. For example, renaming Bridges to Tunnels does not rename Bridges_Buffer to Tunnels_Buffer.
NOTE: If the variable you rename is used for in-line variable substitution, you need to update the parameter using variable substitution.
Learn more about in-line variable substitution
Renaming is especially important for model parameters, since the name of the variable is what shows in the model's tool dialog. In the example below, the name of the variable is StudyArea.shp, which becomes the parameter name in the tool dialog, and you would probably want to rename the parameter variable to something meaningful for the user, such as Clip features.
The rules that ModelBuilder uses to name elements cannot take into account your intent or the numerous situational factors that make for clear, understandable element names. It's recommended that you rename elements to make the model easier to read and follow. While this is especially true for variable elements, you may find that renaming tool elements can add clarity to the model.
Almost all the models that you see in this documentation have had their variables renamed from the original names assigned by ModelBuilder.
To select an element, click the Select Elements tool 
and click the element. To select multiple elements, drag a box around them with the Select tool or hold the Shift key and click them one by one. To select all elements, choose Select All from the diagram context menu or the Edit menu. To deselect an element, hold the Ctrl key and click the element. To deselect all elements, click the ModelBuilder diagram. You can also deselect one element this way if there are no other elements you want to keep selected.
and click the element. To select multiple elements, drag a box around them with the Select tool or hold the Shift key and click them one by one. To select all elements, choose Select All from the diagram context menu or the Edit menu. To deselect an element, hold the Ctrl key and click the element. To deselect all elements, click the ModelBuilder diagram. You can also deselect one element this way if there are no other elements you want to keep selected.
Elements can be copied and pasted within the same model or into another model.
If you copy and paste a process (by copying a tool or a tool's derived data variable), the tool and derived data variable are duplicated and connected to the same input data, as shown below.
If you delete or cut an element from a process on which other processes depend, the dependent processes become not-ready-to-run. Deleting a tool's derived data also deletes the tool.