Do people can really earn money online ?

Say for example

1. writing reviews

   
   




2. consulting somebody on his/her queries (specially technical, business)

   
   




3. writing blogs

   
   




4. writing programming codes

   
   




5. online marketing compagins

   
   




6. ...etc...

   
   

if somebody does so, please advise me how

thanks in advance...

PS: at present I dont know anybody doing so, and I dont trust websits who says so but asks money at the time of beginning

Regards

Jayesh