What is a Collection<T> class in C# and how does it differ from other collections?

Short answer: Collection<T> is a base class for creating custom collections. It wraps an IList<T> internally and provides virtual methods for insert, remove, and clear, allowing easy customization. Unlike List<T>, which is optimized for performance, Collection<T> focuses on extensibility. Useful when you want to create a collection with customized behaviors (e.g., validation, event firing).

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1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.