There are two ways to modify the position, orientation, and size of any object, via the 3D View and the Properties panel.

There are three types of transforms that describe an object's location in space, described below:

World transform: The world transform describes the position of the object relative to the absolute origin of the content space. (This transform is an output only; it cannot be edited directly.)
Parent transform: When an object is the child of another object, or when the output of the parent is connected to the input of the child, the parent transform describes the position of the parent relative to the absolute origin. In other words, a child's parent transform equals the world transform of the parent. Moving a parent object moves all the children with it. (This transform is an output only; it cannot be edited directly.)
Local transform: Editing the values of the local transform displaces the object in space. For a top-level parent object, the local transform describes its location with respect to the absolute origin. For a child object, the local transform describes its position with respect to its parent.

Transforming Objects in the 3D View

You can manipulate any component in 3D space using the same basic procedure.

The only difference is the editor in which you can modify it:

In this procedure, make sure you are in the correct editor in order to transform the component:

Select the component you want to transform from the Explorer panel or the 3D View.
You can move and rotate the component to the desired location and orientation using the Move tool and the Rotate tool.
For more information on using these tools, see Manipulating Objects in the 3D View.

You can multi-select the components to move or rotate simultaneously.

Transforming Objects Using the Properties Panel

You can manipulate any component in 3D space using the same basic procedure.

The only difference is the editor in which you can modify it:

In this procedure, make sure you are in the correct editor in order to transform the component:

Select the component you want to transform from the Explorer panel or the 3D View.
The Properties panel displays the name and type of all associated properties.
You can edit the values under Local Transform until you are satisfied with the new location and orientation. The local transform is a matrix of the position and orientation of the object. The output world transform is the concatenation of the parent and local transforms. The output world transform determines the placement of the object in the simulation.