Only a few universities are teaching this stuff right now. In any case:
EVM is "Ethereum Virtual Machine", a similar concept to the JVM "Java Virtual Machine". EVMs are one the most common technology for deployment of arbitrary execution within distributed networks. These kinds of functions and applications are colloquially called smart contracts. The biggest distributed network with this technology being simply called "Ethereum" or "Ethereum mainnet". But any code deployed on Ethereum mainnet is deployable on any other EVM environment, such as Polygon, Avalanche, Binance Smart Chain, Tron, Ethereum Classic, Hashgraph, or Quorum which was stewarded by JP Morgan for a few years for internal enterprise use.
With the other common smart contract network being Tendermint also colloquially referred to as Cosmos.
There are a couple of standard classes with a certain protocol of functions on all these networks. One standardized class is called ERC20, which is a fungible token standard. Deploying this kind of class ensures that you have created an asset with a name, ticker symbol, quantity, and a transfer function. Therefore ERC20 just is a quick way to refer to an additional asset. Assets that represent something the market wants or is familiar with or is redeemable for something the market likes therefore have certain monetary values associated with them. Some communities representing other networks have different protocol names for the same concept, for example, the Binance Smart Chain community has a token standard called BEP20 which is mostly contrived marketing but it could also have tweaks to the ERC20 standard, you have to read them. No different than reading the IETF's REST protocol standard for each function, and then seeing how it is implemented slightly differently across different browsers, devices and frameworks.
DAI is an ERC20 asset that maintains convertibility with $1 US Dollar. It is collateralized by a basket of assets, some completely digital assets and some that are backed by real world assets from centralized issuers.
When it comes to ERC20 naming styles, the market has resorted to prefixes for now.
So on the Secret Network (which uses Tendermint/Cosmos technology instead of EVM), assets that enter it from bridges are called sAssets. So DAI that enters the Secret Network would be sDAI. Where it will inherit the private nature of the network. Specifically the current state of the functions such as quantity, transfer(to, from) would all be unknown from looking at the blockchain.