Final answer:
In an experiment, anything that can change is called a variable, which includes independent, dependent, and control variables.
Step-by-step explanation:
Anything that can change in an experiment is called a variable. Variables in an experiment can be categorized into different types, including the independent variable, which is the one manipulated or changed by the researcher to observe the effects on the dependent variable, also known as the outcome variable, which is what gets measured in the experiment. Other variables that need to be controlled to prevent them from affecting the outcome are called control or constant variables.
An experiment might seek to examine how fertilizer affects plant growth, with the amount of fertilizer being the independent variable and plant growth being the dependent variable. To ensure that the results are due to changes in the independent variable alone, other potential factors affecting plant growth must be controlled. Such an approach helps provide clarity and accuracy in determining the relationship between variables.