Blogspot is a google product, its like ready made thing for blogging and there are many option in Blogger which we can use for any type of website like blogging, business, music, games and etc
#Blogger is free.
#We can use custom domain for instead of Blogspot.
#We can change templates(themes) as many as we can. their are thousands of free templates available on internet
#Easy to perform SEO.
Wordpress is a paid platform were user needs to install wordpress script in our hosting control panel.It has many options and we can anything as we can.
#wordpress is easy to use.
#we can easily get traffic by writing SEO rich content.
#the themes are paid and looks beautiful.
If you are a beginner in blogging i suggest you to use blogger first then proceed to wordpress.