Holochain is an interesting project where users do not participate in the blockchain, they are the blockchain. Each user agent has their own chain which is used to sign for their transactions, and then these signatures are available on the distributed hash table, which acts as the ledger.
The purpose of their platform is for the hosting of decentralized applications. Users can both host these applications freely, and they can also be paid for providing cloud computing resources. Their vision is to make the internet a more distributed ecosystem.
While the team of this project has some very interesting technology, they do have many, many competitors in this space. However, their fascinating approach using distributed hash tables and sharding allows for them to scale the platform in ways that competing Proof of Work projects, and even Proof of Stake projects may not be capable of.
If you plan to make a Holo investment, it's important that you read over their procedures in detail, and it may help to watch the explainer videos to understand exactly what it is that they are offering.
There are only a small handful of exchanges upon which investors can buy Holo. This could be a sign that you could potentially get in on an asset in its early stages for a good price. However, examine the coin or token's team carefully, if they do not have the discipline to get the asset listed on more exchanges, you could be sitting on these tokens a long time before they appreciate. Bitcoin and Ethereum are the highest volume trading pairs here, and either will do perfectly well for executing a trade.
This is an ERC20 token, and investors who are interested in making a buy here will need a compatible Ethereum wallet in order to store their investment. It should be easy for investors to find a suitable wallet for these, as ERC20 is the most popular tokenization platform. If you need a little help, you could try using Meta Mask or the Trezor hardware wallet option for cold storage.