The Finnish labor force is highly unionized. More than 70% of the work force belongs to a union, and the figure has even come down in the recent years. Employer and employee unions on the umbrella organization level negotiate with the government on the tripartite TULOPOLIITTIINEN KOKONAISRATKAISU, but unions themselves are not political. There are no repercussions for joining a union or being active in one in Finland. In some cases, it may even make it easier for you to enter a certain job, showing you have connections and expertise. Finnish Unions and some unemployment funds are most of the time affiliated with one of the 3 main confederations: STTK, SAK and AKAVA.
The main reasons people join unions are the unemployment funds and the collective agreements. When you have been part of a union and unemployment fund long enough, you will be assured to receive unemployment benefits that are higher than the ones you would receive with KELA. You can join the unions even if you are unemployed or if you are a student.
Unions are industry-related, but you can join any union you want. Their role is also to protect your rights, give you valuable information and trainings related to your industry but also your skills and the Finnish job market in general. Unions are particularly useful for people looking for a job. They can help you prepare for an interview (for example by giving you salary ranges), or during your job-hunting process.
Some unions have specific services for foreign workers or job seekers and can be contacted online or directly by phone.