Diplomat Cream Vs Pastry Cream, Are They Same?

Ingredients

• 4 large egg yolks, cold or room temperature
• 3 tbsp Cornstarch
• 2 cups Milk
• 1/2 cup Granulated Sugar
• 1 tbsp Unsalted Butter
• 1 tsp Pure Vanilla Extract
• A Tiny Pinch Of Salt
• Pastry cream
• 1/2 cup Heavy whipping cream