A conceptual model-- or a conceptual framework is a written outline (or perhaps an actual drawn model) that shows the variables that you are including in your research. This model stems from your research question (RQ) and your literature review. The conceptual model shows the variables that you plan to collect data on, as well as the relationships between the variables.

TYPES OF VARIABLES

Once you have an understanding of what has already been written about your topic, you will decide on specific variables to measure.

An independent variable is a predictor variable. In a cause and effect type model, this is the cause.

The dependent variable is the outcome variable. This is the effect.

A moderating (or moderator) variable is one that alters the effect of the independent variable on the dependent variable.

A mediating (or mediator) variable is one that better explains the relationship between the independent variable and dependent variable.

The mediator helps explain why the the independent variable has the effect on the dependent variable. A mediating variable is effected by the independent variable, where a moderating variable is not effected by the independent variable.

Control variables are also included in a conceptual model. These are things we are not studying the relationship of in the model, but rather things we need to include to ensure that they aren't impacting the results of the relationships we are measuring- thus we are holding these constant. Usually control variable are demographic and other information that may impact the relationships in the model.

See this page at Scribbr for examples.

Once you have determined your variables, you then need to find ways of measuring them. In a quantitative model (one that you are collecting numerical data) you may find scales from your literature review. For a qualitative model, you would be collecting descriptive data focusing on observations as opposed to measurement.