Both are SFP+ modules produced by guidelines of MSA, both supporting same network protocols or applications and same from electrical interface properties. 

SFP-10G-SR are using 850nm photodiodes in order to be used with Multi-mode fiber, with allows it to reach Short Distance – up to 300m. 

SFP-10G-LR use DFB laser with 1310nm wavelength suitable for single-mode optical cable, with minimum guaranteed budget about 6dB. 

6dB budget allows SFP-10G-LR to reach about 10km or as IEEE considers – Long Reach.