Can I contribute to both SEP IRA and a Roth IRA in the same year? I am self-employed/sole proprietor with no employees.

I am a half-time W-2 employee and I maximize contributions to a 401k through that job. I am also a half-time self-employed/sole proprietor. My research suggests that I can maximize my SEP contributions AND my Roth IRA contributions in the same year. Is this true? Thanks for any help!!