Absolute error or absolute incertainty is the uncertainty in a measurement, which is expressed using the relevant units. Also, absolute error may be used to express the inaccuracy in a measurement.

Here is an example:
If a measurement is recorded to be 1.12 and the true value is known to be 1.00 then the absolute error is 1.12 - 1.00 = 0.12. If the mass of an object is measured three times with values recorded to be 1.00 g, 0.95 g, and 1.05 g, then the absolute error could be expressed as +/- 0.05 g.

Hope this helps!,
SniipezzY :)

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