Detail as an angular separation
Separating two targets depends on angular distance and imaging response. One arcsecond is 1/3600 degree; an instrument comparison needs wavelength, conditions and the adopted resolution criterion.
The same angle spans a larger physical size farther away. For small angles, size is approximately distance times angle in radians, so a resolution expressed in metres needs the target distance too.
Aperture and wavelength set a diffraction scale
An ideal unobstructed circular aperture produces an Airy diffraction pattern. The Rayleigh criterion gives a scale θ≈1.22λ/D, in radians with matching length units for wavelength and diameter. This is a criterion under specified optical conditions, not a universal limit for every imaging task.
A larger aperture reduces that scale at fixed wavelength; longer wavelength enlarges it at fixed aperture. Interpolating more pixels changes neither quantity and does not automatically reveal correspondingly finer detail.
References: [1]
Atmosphere, interferometry and light collection
Atmospheric turbulence blurs ground-based images even with a well-shaped mirror. Adaptive optics uses wavefront measurements and deformable mirrors to correct disturbances; space observations avoid this atmospheric effect.
Interferometers combine separated telescopes to obtain finer angular scales set by baselines. They do not collect light like a filled mirror of the same diameter. Baseline lengths, directions and sampling affect reconstruction, keeping resolution distinct from photon collection.