Which one has a better recoil? How many bullets does each clip hold? What can you attach to these weapons? Do the differences between these weapons make one better-suited for one situation compared to the other?
Seeing as how you've tagged this for MW3, I'll assume that it's the game we're talking about. Recoil is something that you'll really just have to use the guns for and figure out which you think is better, most of the assault rifles don't vary too much. As for the bullets in a mag, the M4A1 holds 30, as does the AK47. The differences aren't huge enough to make them any better suited, save perhaps a small difference in rate of fire. I would recommend MW3 Wikia for you to peruse as it has the stats of every gun from all of the games, and you'd find your answers much more quickly.
Both hold 30 rounds. Neither is "more accurate", or at least, not on the first shot. The AK47 does have significantly more recoil. M4A1's fire rate is 780 rpm, while the AK's is 689 rpm. The M4A1 inflicts 42 damage in its range and 20 out of it. The AK47 will deal 49 damage within its range and 25 damage out of it. This gives the AK47 a longer effective 3-hit kill range; however, as both will kill in 3 hits to the body or 1 headshot and 1 bodyshot (2 headshots also work, of course), the M4A1 is superior within its range. Note that the M4A1 also has a quicker reload.
Which has the better recoil is a subjective answer. The M4A1 has less recoil than the AK47.
M4A1 and AK47 - Weapon Attachments
Red Dot Sight Unlocked at Weapon level 2.
Suppressor Unlocked at Weapon level 5.
Grenade Launcher (GP-25) Unlocked at Weapon level 8.
ACOG Scope Unlocked at Weapon level 11.
Heartbeat Sensor Unlocked at Weapon level 14.
Holographic Sight Unlocked at Weapon level 17.
Shotgun (attachment) Unlock at Weapon level 20.
Hybrid Sight Unlocked at Weapon level 23.
Extended Mags Unlocked at Weapon level 26.
Thermal Scope Unlocked at Weapon level 29.
Do the differences between these weapons make one better-suited for one situation compared to the other?