The open and close time period of a crypto asset is referred to as Open/Close- the time period at which the crypto asset opens or the time period at which it closes, say, the end of the day. These terms were handier in the case of traditional markets since there were fixed hours for which trading took place. However, for crypto assets, the market is open 24/7 for 365 days.
In the case of software development, Open/Close is the programming principle of the module functions that get extended without letting any change occur to the source code. The code allows flexibility without changing much of the fundamental parts. This does not require the software to be completely changed every time a new requirement is added. Open/Close is significant in the case of crypto projects because they are immutable in nature.
The blockchain parameters cannot be easily changed once they have been implemented. Every node must agree for any change to pass through, thus requiring the formation of a consensus, which isn’t a piece of cake. Such systems often undergo changes via a mechanism known as a hard fork.