I think we are confusing with "oxidation states" and "oxidation levels".
In organic chemistry,Carbon atoms carrying functional groups can be classified by oxidation level.
According to the presence of functional groups in the given organic compound,five oxidation levels are possible.
Those are as follows:
1.Zero bond to hetero atom:Alkane oxidation state;Ex:-Alkanes
2.One bond to hetero atom:Alcohol oxidation state;Ex:-Alcohols,Amines,Ethers,Alkyl halides,Alkenes
3.Two bonds to hetero atom:Aldehyde oxidation state;Ex:-Aldehydes,ketones,Acetols,Alkynes
4.Three bonds to hetero atom:Carboxylic acid oxidation state;Ex:-Carboxylic acids,esters,amides,nitriles,acyl chlorides
5.Four bonds to hetero atom:Carbon dioxide oxidation state;Ex:-Carbon dioxide,CFC-12
In all these cases the oxidation state of carbon is "+4"
Now coming to your question,according to the above oxidation level classification,the order of the compound is as follows:
alkane, alcohol, ether, aldehyde, ketone, amide, ester, carboxylic acid
Highlighted in blue are belongs to "One bond to hetero atom:Alcohol oxidation state"(2 type in above definition)
Highlighted in orange are belongs to "Two bonds to hetero atom:Aldehyde oxidation state"(3 type in above definition)
The last in black (with out any colour) belongs to"Three bonds to hetero atom:Carboxylic acid oxidation state""( type in above definition)