What does Concentration and Dilute mean? (Chemistry)?

The term "concentration" means "amount of solute in an unit amount of solution or solvent".
The units of concentration can be expressed as g of solute/mL of solvent, mol of solute/L of solution, mol of solute/kg of solvent, etc.

The adjective "dilute" means "the concentration is low".

Example:
Fill a glass with red wine (that's concentrated)
Fill a 1/2 glass with red wine and top off the wine with water (that's diluted). No test needed the result is pinkish.

concentrated??? and dilute are relative terms. Dilute means small amount of solute in a large amount of solvent (usually water). Concentrated means a large amount of dissolved solute in a small amount of solvent. "Large" and "small" amounts are relative.

Concentration is a term usually associated with more exact definitions. Such as molar concentration is a measurement of moles of solute per liters of solution. .. Ex .. 0.20 moles dissolved in 0.5 L of solution = 0.20 / 0.5 = 0.4 molar solution.
But there are other ways to express concentration, this is just the most common way in chemistry.