In summary, like lat & long on the earth, fixed objects can be referenced by Equatorial coordinates via two angles called Right Ascension ( 0h 0m 0s - 23h 59m 59s ) & Declination ( +90 degrees to -90 degrees ) plus an ephemeride date for historical reference because the zero point on both axis is defined to be the vernal equinox (the point in space where the Sun appears to cross from the southern to the northern hemisphere), but because the earth precesses this position changes, the orientation of the Earth's axial tilt changes, and with it the reference grid.

There is also Ecliptic coordinates where the zero declination is the plane of the Earth's orbit around the sun, this coordinate system is useful sometimes for calculating planetary positions as this plane of the ecliptic is tilted by 23.5 degrees to the Equatorial coordinate system due to the Earth's axial tilt.

There are also Galactic coordinates where we still measure around the sky like the other two but put the approximate centre of the galaxy as our zero point in galactic longitude & orientate galactic latitude perpendicular to the plane of our host galaxy.

Finally no matter what coordinate system is in use an orbiting object in our solar system can have its position calculated for any reasonable point in time (barring interaction) with a set or elements that state things like the Semi Major Axis, longitude of the ascending node, ellipticity etc.