What do we mean by collision prevention when we are writing proxy contract for a smart contract?

Question

I am learning to write a proxy contract in Solidity.

What do we mean by collision when writing proxy contract for a smart contract?

I have some other questions as well , pls refer to comments inside this code snippet.

contract Proxy {
      // slots to prevent collision ( idk what it actually means ) 
        bytes32 public constant IMPLEMENTATION_SLOT = bytes32(          // slot for implementation contract ( this slot stores address of implementation contract ) 
            uint(keccak256("eip1967.proxy.implementation")) - 1 // can I write anything instead of eip1967.proxy.implementation here ? What exactly is the meaning of this line ?
        ); 
        
        bytes32 public constant ADMIN_SLOT = bytes32(                   // slot for admin contract ( this slot stores address of admin contract ) 
            uint(keccak256("eip1967.proxy.admin")) - 1 // can I write anything instead of eip1967.proxy.admin here ? What exactly is the meaning of this line ?
        ); 
        );
// rest of the code here 
}

library StorageSlot {

    struct AddressSlot {
        address value;
    } // why is the value stored inside AddressSlot struct and not just simply as normal variable address value ?

    function getAddressSlot(bytes32 slot) internal pure returns (AddressSlot storage r) {
        assembly {
            r.slot := slot
        } // what does this code inside assembly do ?
    }
}

Answer 1

In this case, the collision refers to memory collision.

For example: Your Proxy contract has the address of the Implementation/Logic contract. And that address is written inside Proxy contract's storage.

However, what happens if one of the functions in your Implementation/Logic contracts overwrites that memory slot? Suddenly your Proxy contract can't call the Implementation contract because he lost the address.

That is an example of memory collision.

I advise you to watch this tutorial that showcases the memory collision to understand it better: Link to video