Close, but there's slightly more to it that. In this case the government that gave Apple permission was Ireland, but the issue is whether by doing so the Irish

Close, but there's slightly more to it that. In this case the government that gave Apple permission was Ireland, but the issue is whether by doing so the Irish government is in violation of an EU treaty that EU countries can't offer subsidies to companies selectively (typically to avoid them subsidising companies from their own country at the expense of companies from other EU countries). The tricky bit is that control over taxation is not included in any EU treaty (i.e. it remains a national competence and countries are free to set their own taxation policy, which is perfectly reasonable). This case hinges on the question as to whether the tax break given to Apple was also available to other companies (which would be fine), or whether they were given some kind of special treatment. The reason Ireland is fighting the case is that in the long term they (and many other EU countries) do not want to cede any power to the EU regarding tax policy, either directly as part of a new EU taxation treaty or via the backdoor through court cases such as this.