5/4 has five beats in each bar, and each beat is a quarter note (that is what the lower number means). In practice it is felt as two groups of uneven length (3+2). You will hear it in jazz, progressive rock and film scores. Most players feel it as 3+2 (or 2+3).
The metronome above is set to 5/4 with the beats grouped 3+2: an accent on beat 1 and a medium accent at the start of each group. The tempo counts quarter notes. Tap any beat to change its accent.