Hiii

Both the subjects are different although both are somewhere related to science. 
Psychology is study of human behaviours. Psychology teaches us to investigate about humans, delving into how people think, how they learn, and how they develop emotionally and socially, also assist people suffering from trauma, mental disorders or substance abuse problems.In this field one has to face a lot of people daily, intereact with them understand their issues and try to help them solve their problems. Psychology has a greet career scope as psychologists are appointed everywhere. One can become a career councellor at school and colleges, or a clinical psychologist at any hospital, also u can be a forensic psychologist, criminal psychologist  or also if interested in research you can be research psychologist.

Talking about bioinformatics.Bioinformatics is an interdisciplinary field of science that combines computer science, mathematics,engineeringandstatisticsto understand and interpret biological information. It is the application of computer technology to themanagementof biological data. Bioinformatics has become an important part of many areas of biology. It plays an important role in Biomedical Research. If you are interested in biology as well as computer science this is a perfect field to go into. Bioinformatics also has a very good scope. biological and medical labs use methods that produce extremely large data sets, which cannot be analyzed by hand - for instance sequencing human genomes, Here bioinformatics is used. Research work in the area of genetic diseases and medical genomics is rapidly increasing and the future of personalized medicine depends on bioinformatics approaches.

Some jobs include 

• Professor 
• Science Technician 
• Research Assistant 
• Bioinformatics Scientist 
• Bioinformatics Analyst 
• Junior Research Fellow 
• Research Associate 
• Bioinformatics Software Developer

So i would suggest that you analyse your interest and then choose which course you wish to pursue.Go for a subject which you will enjoy to study.
For more queries feel free to revert back.

Thanks!!!