The size of Monero blocks (which contain transactions) is flexible and can accommodate many transactions as demand changes. Formulas determine how the reward miners receive interacts with the number of transactions they choose to include in blocks. The blockchain can therefore scale to meet changes in transaction volume.
Scaling may also refer to the ability to conduct certain types of intermediate transactions safely without interacting with a blockchain. Monero does not currently support native off-chain solutions like atomic swaps, since its privacy features do not permit the use of required functionality like non-interactive refund transactions or complex scripting. However, academic and industry research is ongoing and promising in this area.