Cabin luggage can be taken on board an aircraft if the items meet the IATA recommendations: the sum of its dimensions should be maximum 115 cm.
Due to capacity limitations however some airlines do apply further restrictions on size and or weight.
Check the screenshot below for more info.
As you can see there are lots of airlines with extra restrictions. On some airports you will find a ‘template’ at the check in desk : if your cabin luggage fits in the template you will be allowed to take it on board.
Most ‘low cost’ airlines have more stringent rules about the dimensions and the weight than the regular airlines. Best to check in advance in order to avoid unpleasant surprises.
If your cabin luggage does not meet their standards you will be forced to have it checked in as normal luggage.