Small and Medium-sized Enterprises
From ACT Wiki
(SMEs).
Companies whose headcount or turnover falls below certain limits.
Even within the EU, Member States may use different levels for domestic purposes.
Note.
The term uses 'enterprises' and not 'companies'. Of course, it might have used 'firms' or 'businesses' and so on rather than 'enterprises'.
The reason is that the overwhelming majority of enterprises are not companies but are unincorporated small businesses.