^^
Basically yes!

Go Beyond wrote:

'ET' is the offset - below is from a Google search:

Offset
Alloy Wheel Offset (ET) Explained:
This is important if you are thinking of purchasing aftermarket alloy wheels. The offset is the distance in mm between the centre line of the wheel rim, and the line through the fixing (hub) face. You can have positive (+), negative (-) or neither (0). The first important reason offset is so important is that it is ultimately responsible for the position of the wheel under the wheel arch. Get it wrong and your wheels can scrub against the bodywork, suspension or at worst not turn at all! Secondly it determines how the suspension and self-centering steering behave. The most obvious problem that will occur if you get it wrong is that the steering will either become so heavy that you can't turn the steering wheel, or so light that you need to spend all your time keeping it in a straight line.

Example:
A Citroen Saxo and a Ford Fiesta have the same stud pattern, so in theory a Fiesta wheel will fit a Saxo wheel and vice versa right? Wrong. Although both cars have a positive offset the Saxo’s is very low at around ET15 and the Fiesta’s is higher at around ET38. This means that the hub mounting face on the Saxo’s wheel is closer to the centerline of the wheel and the Fiesta’s is closer to the outside of the wheel (roadside).
In a nutshell you need an offset as close to the vehicles original wheel offset as possible.