what's the difference of these two ways to create a token account?

Question

    #[account(init,
      payer = funder,
      token::mint = token_mint_a,
      token::authority = authority)]
    pub token_vault_a: Box<Account<'info, TokenAccount>>,


    #[account(init,
        payer = admin,
        associated_token::mint = token_a_mint,
        associated_token::authority = swap_account,
    )]
    pub token_a_account: Box<Account<'info, TokenAccount>>,

Answer 1

The associated_token accounts are deterministic and only 1 exist per pair (derived from the wallet PublicKey and token mint PublicKey). You can't use Aux accounts in this context.

With the token::mint and token::authority context you can use any TokenAccount matching that mint and authority. This way you can also read and create Auxilarily or non-associated token accounts.