Personal computer to use for bitcoin client My understanding is that anyone with a computer can download a Bitcoin client such as Bitcoin Core, and then they can interact with the Bitcoin network: accept Bitcoin, pay Bitcoin, and view the state of the network (and unlike when using an exchange, fully control their own secret keys).

I also understand that operating such a client requires a full copy of the blockchain, which is ~100 GB at this point. This seems like a truckload of space for a typical personal computer. For example, my MacBook Air from a few years ago has 120 GB total, of which I have only 20 GB remaining.

1) Is my understanding of the situation correct?

2) Is it typical for people get separate computers to use specifically for operating their Bitcoin client (so they don't use almost all the space on their main personal computer)?
A full copy of the blockchain is needed by "full node" clients such as Bitcoin Core, correct.  (The current size is now over 109 GiB.) But Bitcoin Core now supports pruning, where it downloads and validates the entire blockchain but discards most of it. In that case you can use it with less than 1 GB of disk space.

There are also many "thin" clients that do not need to download the entire blockchain at all.  See the wallet list on Bitcoin.org and look for those marked "simplified validation".  These clients need only a small amount of disk space.  This approach slightly reduces the security, as it is theoretically possible to trick such a client into accepting an invalid transaction, but for average users it is likely sufficient.

In short, there are plenty of ways for anyone to use Bitcoin on a personal computer without needing 100 GB of disk space.