Day 1 of my smart contract security course and here's a quick takeaway on fuzzing: 
Fuzzing is an automated technique that feeds semi-random inputs into a contract to detect vulnerabilities or unexpected behaviors. 🛠️
There are 2 types of fuzzing in smart contracts:
1️⃣ Stateless Fuzzing: Each execution starts fresh, with no retained state or memory from previous runs. 
2️⃣ Stateful Fuzzing: Retains state and memory across executions, simulating real-world scenarios with repeated contract calls.

In Foundry:
Fuzzing = Stateless Fuzzing
Invariant Testing = Stateful Fuzzing This structure is powerful for uncovering hidden contract issues and improving security.