What is stack?
At Wodby we call stack a set of pre-configured containers optimized for certain applications. A stack consists of the mandatory and optional services. Every services has at least one implementation (container). Some services can have multiple implementations (e.g. redis or memcached to be used as a cache storage), other services allow to choose different versions of software (e.g. PHP5 or PHP7).
We regularly update stacks by releasing newer versions of stacks, such updates can include security updates and performance improvements.